This is a list of meteorology topics. The terms relate to

meteorology Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did no ...

, the

interdisciplinary Interdisciplinarity or interdisciplinary studies involves the combination of multiple academic disciplines into one activity (e.g., a research project). It draws knowledge from several other fields like sociology, anthropology, psychology, ec ...

scientific study of the

atmosphere An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A ...

that focuses on

weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the ...

processes and forecasting. (see also:

List of meteorological phenomena This glossary of meteorology is a list of terms and concepts relevant to meteorology and atmospheric science, their sub-disciplines, and related fields. A ...

)

A

advection In the field of physics, engineering, and earth sciences, advection is the transport of a substance or quantity by bulk motion of a fluid. The properties of that substance are carried with it. Generally the majority of the advected substance is al ...

aeroacoustics Aeroacoustics is a branch of acoustics that studies noise generation via either turbulent fluid motion or aerodynamic forces interacting with surfaces. Noise generation can also be associated with periodically varying flows. A notable example of th ...

aerobiology Aerobiology (from Greek ἀήρ, ''aēr'', "air"; βίος, ''bios'', "life"; and -λογία, ''-logia'') is a branch of biology that studies organic particles, such as bacteria, fungal spores, very small insects, pollen grains and viruses, ...

aerography (meteorology) Aerography is the production of weather charts. The information is supplied by radiosonde observations, principally. ''Constant-pressure'' charts are routinely constructed at standard air pressures. Standard air pressures are 850, 700, 500, 400, ...

aerology Atmospheric science is the study of the Earth's atmosphere and its various inner-working physical processes. Meteorology includes atmospheric chemistry and atmospheric physics with a major focus on weather forecasting. Climatology is the study of ...

air parcel In fluid dynamics, within the framework of continuum mechanics, a fluid parcel is a very small amount of fluid, identifiable throughout its dynamic history while moving with the fluid flow. As it moves, the mass of a fluid parcel remains constant, ...

(in meteorology) *

air quality index An air quality index (AQI) is used by government agencies to communicate to the public how polluted the air currently is or how polluted it is forecast to become. AQI information is obtained by averaging readings from an air quality sensor, wh ...

(AQI) * airshed (in meteorology) *

American Geophysical Union The American Geophysical Union (AGU) is a 501(c)(3) nonprofit organization of Earth, atmospheric, ocean, hydrologic, space, and planetary scientists and enthusiasts that according to their website includes 130,000 people (not members). AGU's ...

(AGU) *

American Meteorological Society The American Meteorological Society (AMS) is the premier scientific and professional organization in the United States promoting and disseminating information about the atmospheric, oceanic, and hydrologic sciences. Its mission is to advance th ...

(AMS) *

anabatic wind An anabatic wind, from the Greek '' anabatos'', verbal of ''anabainein'' meaning moving upward, is a warm wind which blows up a steep slope or mountain side, driven by heating of the slope through insolation.anemometer In meteorology, an anemometer () is a device that measures wind speed and direction. It is a common instrument used in weather stations. The earliest known description of an anemometer was by Italian architect and author Leon Battista Alberti ...

annular hurricane An annular tropical cyclone is a tropical cyclone that features a normal to large, symmetric eye surrounded by a thick and uniform ring of intense convection, often having a relative lack of discrete rainbands, and bearing a symmetric appearanc ...

anticyclone An anticyclone is a weather phenomenon defined as a large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere as viewed from ...

(in meteorology) *

apparent wind Apparent wind is the wind experienced by a moving object. Definition of apparent wind The ''apparent wind'' is the wind experienced by an observer in motion and is the relative velocity of the wind in relation to the observer. The ''velocity ...

Atlantic Oceanographic and Meteorological Laboratory The Atlantic Oceanographic and Meteorological Laboratory (AOML), a federal research laboratory, is part of the National Oceanic and Atmospheric Administration's (NOAA) Office of Oceanic and Atmospheric Research (OAR), located in Miami in the Unite ...

(AOML) *

Atlantic hurricane season The Atlantic hurricane season is the period in a year from June through November when tropical cyclones form in the Atlantic Ocean, referred to in North American countries as hurricanes, tropical storms, or tropical depressions. In addition ...

* atmometer *

Atmospheric Model Intercomparison Project Atmospheric Model Intercomparison Project (AMIP) is a standard experimental protocol for global atmospheric general circulation models (AGCMs). It provides a community-based infrastructure in support of climate model diagnosis, validation, intercomp ...

(AMIP) *

Atmospheric Radiation Measurement The Atmospheric Radiation Measurement Climate Research Facility (ARM Climate Research Facility) is a multi-laboratory United States Department of Energy scientific user facility used for national and international global climate research efforts. ...

(ARM) * (atmospheric boundary layer BL

planetary boundary layer In meteorology, the planetary boundary layer (PBL), also known as the atmospheric boundary layer (ABL) or peplosphere, is the lowest part of the atmosphere and its behaviour is directly influenced by its contact with a planetary surface. On Ear ...

(PBL) *

atmospheric chemistry Atmospheric chemistry is a branch of atmospheric science in which the chemistry of the Earth's atmosphere and that of other planets is studied. It is a multidisciplinary approach of research and draws on environmental chemistry, physics, meteorol ...

atmospheric circulation Atmospheric circulation is the large-scale movement of air and together with ocean circulation is the means by which thermal energy is redistributed on the surface of the Earth. The Earth's atmospheric circulation varies from year to year, bu ...

atmospheric convection Atmospheric convection is the result of a parcel-environment instability, or temperature difference layer in the atmosphere. Different lapse rates within dry and moist air masses lead to instability. Mixing of air during the day which expands the ...

atmospheric dispersion modeling Atmospheric dispersion modeling is the mathematical simulation of how air pollutants disperse in the ambient atmosphere. It is performed with computer programs that include algorithms to solve the mathematical equations that govern the pollutant ...

atmospheric electricity Atmospheric electricity is the study of electrical charges in the Earth's atmosphere (or that of another planet). The movement of charge between the Earth's surface, the atmosphere, and the ionosphere is known as the global atmospheric electr ...

atmospheric icing Atmospheric icing occurs in the atmosphere when water droplets suspended in air freeze on objects they come in contact with. It is not the same as freezing rain, which is caused directly by precipitation. Icing conditions can be particularly dang ...

atmospheric physics Within the atmospheric sciences, atmospheric physics is the application of physics to the study of the atmosphere. Atmospheric physicists attempt to model Earth's atmosphere and the atmospheres of the other planets using fluid flow equations, chem ...

atmospheric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, ...

atmospheric sciences Atmospheric science is the study of the Earth's atmosphere and its various inner-working physical processes. Meteorology includes atmospheric chemistry and atmospheric physics with a major focus on weather forecasting. Climatology is the study ...

atmospheric stratification The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...

atmospheric thermodynamics Atmospheric thermodynamics is the study of heat-to- work transformations (and their reverse) that take place in the earth's atmosphere and manifest as weather or climate. Atmospheric thermodynamics use the laws of classical thermodynamics, to des ...

atmospheric window An atmospheric window is a range of wavelengths of the electromagnetic spectrum that can pass through the atmosphere of Earth. The optical, infrared and radio windows comprise the three main atmospheric windows. The windows provide direct channels ...

(see under

Threats A threat is a communication of intent to inflict harm or loss on another person. Intimidation is a tactic used between conflicting parties to make the other timid or psychologically insecure for coercion or control. The act of intimidation for co ...

)

B

ball lightning Ball lightning is a rare and unexplained phenomenon described as luminescent, spherical objects that vary from pea-sized to several meters in diameter. Though usually associated with thunderstorms, the observed phenomenon is reported to last ...

balloon (aircraft) In aeronautics, a balloon is an unpowered aerostat, which remains aloft or floats due to its buoyancy. A balloon may be free, moving with the wind, or tethered to a fixed point. It is distinct from an airship, which is a powered aerostat tha ...

baroclinity In fluid dynamics, the baroclinity (often called baroclinicity) of a stratified fluid is a measure of how misaligned the gradient of pressure is from the gradient of density in a fluid. In meteorology a baroclinic flow is one in which the densi ...

* barotropity *

barometer A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis ...

("to measure atmospheric pressure") *

berg wind Berg wind (from Afrikaans ''berg'' "mountain" + ''wind'' "wind", i.e. a mountain wind) is the South African name for a katabatic wind: a hot dry wind blowing down the Great Escarpment from the high central plateau to the coast. Overview When ...

biometeorology Biometeorology is the interdisciplinary field of science that studies the interactions between the biosphere and the Earth's atmosphere on time scales of the order of seasons or shorter (in contrast with bioclimatology). Examples of relevant proc ...

blizzard A blizzard is a severe snowstorm characterized by strong sustained winds and low visibility, lasting for a prolonged period of time—typically at least three or four hours. A ground blizzard is a weather condition where snow is not falling ...

bomb (meteorology) Explosive cyclogenesis (also referred to as a weather bomb, meteorological bomb, explosive development, bomb cyclone, or bombogenesis) is the rapid deepening of an extratropical cyclonic low-pressure area. The change in pressure needed to clas ...

buoyancy Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the ...

Bureau of Meteorology The Bureau of Meteorology (BOM or BoM) is an executive agency of the Australian Government responsible for providing weather services to Australia and surrounding areas. It was established in 1906 under the Meteorology Act, and brought together ...

(in Australia)

C

* Canada Weather Extremes *

Canadian Hurricane Centre The Canadian Hurricane Centre (CHC; french: Centre canadien de prévision des ouragans) is an organisation that monitors and warns of the threat of tropical cyclones such as hurricanes and tropical storms. CHC is a division of the Meteorological Se ...

(CHC) *

Cape Verde-type hurricane A Cape Verde hurricane or Cabo Verde hurricane is an Atlantic hurricane that originates at low-latitude in the deep tropics from a tropical wave that has passed over or near the Cape Verde islands after exiting the coast of West Africa. The avera ...

capping inversion A capping inversion is an elevated inversion layer that caps a convective planetary boundary layer. The boundary layer is the part of the atmosphere which is closest to the ground. Normally, the sun heats the ground, which in turn heats th ...

(in meteorology) (see "severe thunderstorms" in paragraph 5) *

carbon cycle The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Carbon is the main component of biological compounds as well as a major compon ...

carbon fixation Biological carbon fixation or сarbon assimilation is the process by which inorganic carbon (particularly in the form of carbon dioxide) is converted to organic compounds by living organisms. The compounds are then used to store energy and as ...

carbon flux The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Carbon is the main component of biological compounds as well as a major componen ...

carbon monoxide Carbon monoxide ( chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simpl ...

(see under Atmospheric presence) *

ceiling balloon A ceiling balloon also called a pilot balloon or pibal, is used by meteorologists to determine the height of the base of clouds above ground level during daylight hours. In the past, and sometimes today, a theodolite was used to track the ball ...

("to determine the height of the base of clouds above ground level") *

ceilometer A ceilometer is a device that uses a laser or other light source to determine the height of a cloud ceiling or cloud base. Ceilometers can also be used to measure the aerosol concentration within the atmosphere. A ceilometer that uses laser light ...

("to determine the height of a cloud base") *

celestial coordinate system Astronomical coordinate systems are organized arrangements for specifying positions of satellites, planets, stars, galaxies, and other celestial objects relative to physical reference points available to a situated observer (e.g. the true hor ...

celestial equator The celestial equator is the great circle of the imaginary celestial sphere on the same plane as the equator of Earth. This plane of reference bases the equatorial coordinate system. In other words, the celestial equator is an abstract proj ...

* celestial horizon (rational horizon) *

celestial navigation Celestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current physical position in space (or on the surface o ...

(astronavigation) *

celestial pole The north and south celestial poles are the two points in the sky where Earth's axis of rotation, indefinitely extended, intersects the celestial sphere. The north and south celestial poles appear permanently directly overhead to observers a ...

Celsius The degree Celsius is the unit of temperature on the Celsius scale (originally known as the centigrade scale outside Sweden), one of two temperature scales used in the International System of Units (SI), the other being the Kelvin scale. The d ...

Center for Analysis and Prediction of Storms The Center for Analysis and Prediction of Storms (CAPS) was established at the University of Oklahoma in 1989 as one of the first eleven National Science Foundation Science and Technology Centers. Located at the National Weather Center in Norman, ...

(CAPS) (in Oklahoma in the US) *

Center for the Study of Carbon Dioxide and Global Change The Center for the Study of Carbon Dioxide and Global Change is a 501(c)(3) non-profit organization based in Tempe, Arizona. It is seen as a front group for the fossil fuel industry, and as promoting climate change denial. The Center produces a w ...

(based in Arizona in the US) * (Central America Hurricane of 1857: see)

SS Central America SS ''Central America'', known as the Ship of Gold, was a sidewheel steamer that operated between Central America and the East Coast of the United States during the 1850s. She was originally named the SS ''George Law'', after George Law of ...

(Ship of Gold) *

Central Florida Tornado of February 2007 The 2007 Groundhog Day tornado outbreak was a localized but devastating tornado event that took place in central Florida early on February 2, 2007. Early morning temperatures had risen well above average for the season; combined with increased m ...

Certified Consulting Meteorologist Certified Consulting Meteorologist (CCM) is the title of a person designated by the American Meteorological Society (AMS) and CCM Board to possess the attributes of Knowledge, Experience, and Character as these pertain to the field of meteorology ...

chaos theory Chaos theory is an interdisciplinary area of scientific study and branch of mathematics focused on underlying patterns and deterministic laws of dynamical systems that are highly sensitive to initial conditions, and were once thought to hav ...

(see "butterfly effect" under

Chaotic dynamics Chaotic was originally a Danish trading card game. It expanded to an online game in America which then became a television program based on the game. The program was able to be seen on 4Kids TV (Fox affiliates, nationwide), Jetix, The CW4Kids ...

) * (Chapman cycle: see) ozone-oxygen cycle * chemtrail theory *

Chicago Climate Exchange The Chicago Climate Exchange (CCX) was a voluntary, legally binding greenhouse gas reduction and trading system for emission sources and offset projects in North America and Brazil. CCX employed independent verification, included six greenhous ...

(CCX) *

chinook wind Chinook winds, or simply Chinooks, are two types of prevailing warm, generally westerly winds in western North America: Coastal Chinooks and interior Chinooks. The coastal Chinooks are persistent seasonal, wet, southwesterly winds blowing in from ...

(see "inversion smog" under Chinooks and health) *

Henry Helm Clayton Henry Helm Clayton (1861–1946) was an American meteorologist and weather forecaster. Biography Clayton was born on March 12, 1861, in Murfreesboro, Tennessee.clear-air turbulence In meteorology, clear-air turbulence (CAT) is the turbulent movement of air masses in the absence of any visual clues, such as clouds, and is caused when bodies of air moving at widely different speeds meet. The atmospheric region most suscept ...

(CAT) *

climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...

Climate Diagnostics Center The Earth System Research Laboratories (ESRL) is an alliance of four NOAA scientific labs, all located in the David Skaggs Research Center on the Department of Commerce campus in Boulder, Colorado. Organized under NOAA’s Office of Oceanic and ...

(in the US) *

climate engineering Climate engineering (also called geoengineering) is a term used for both carbon dioxide removal (CDR) and solar radiation management (SRM), also called solar geoengineering, when applied at a planetary scale.IPCC (2022Chapter 1: Introduction and ...

* (climate forcing: see)

radiative forcing Radiative forcing (or climate forcing) is the change in energy flux in the atmosphere caused by natural or anthropogenic factors of climate change as measured by watts / metre2. It is a scientific concept used to quantify and compare the extern ...

* Climate Group * climate house *

climate model Numerical climate models use quantitative methods to simulate the interactions of the important drivers of climate, including atmosphere, oceans, land surface and ice. They are used for a variety of purposes from study of the dynamics of the c ...

* climate modeller * Climate Monitoring and Diagnostics Laboratory (CMDL) (in the US) * Climate Outreach and Information Network (COIN) (British charity) * (climate parameters, forcings and feedbacks: see)

parametrization (climate) Parameterization in a weather or climate model in the context of numerical weather prediction is a method of replacing processes that are too small-scale or complex to be physically represented in the model by a simplified process. This can be contr ...

Climate Prediction Center The Climate Prediction Center (CPC) is a United States federal agency that is one of the National Centers for Environmental Prediction, which are a part of the National Oceanic and Atmospheric Administration's National Weather Service. CPC is hea ...

(CPC) * (climate science: see)

climatology Climatology (from Greek , ''klima'', "place, zone"; and , '' -logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. This modern field of stu ...

climate sensitivity Climate sensitivity is a measure of how much Earth's surface will cool or warm after a specified factor causes a change in its climate system, such as how much it will warm for a doubling in the atmospheric carbon dioxide () concentration. In te ...

* (climate simulation: see)

* climate surprise * (climate techno-fix: see)

* (climate theory: see)

Charles de Secondat, Baron de Montesquieu Charles Louis de Secondat, Baron de La Brède et de Montesquieu (; ; 18 January 168910 February 1755), generally referred to as simply Montesquieu, was a French judge, man of letters, historian, and political philosopher. He is the principal ...

(see "climate theory" in paragraph 3 under

Political views An ideology is a set of beliefs or philosophies attributed to a person or group of persons, especially those held for reasons that are not purely epistemic, in which "practical elements are as prominent as theoretical ones." Formerly applied pri ...

) * (climate variability: see)

* (climate warming: see)

global warming In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...

* (climate weapon: see)

Weather modification Weather modification is the act of intentionally manipulating or altering the weather. The most common form of weather modification is cloud seeding, which increases rain or snow, usually for the purpose of increasing the local water supply. W ...

(see under In the military) *

climateprediction.net climate''prediction''.net (CPDN) is a volunteer computing project to investigate and reduce uncertainties in climate modelling. It aims to do this by running hundreds of thousands of different models (a large climate ensemble) using the donate ...

(CPDN) (distributed computing project) *

climatic determinism Environmental determinism (also known as climatic determinism or geographical determinism) is the study of how the physical environment predisposes societies and states towards particular development trajectories. Jared Diamond, Jeffrey Herbst, ...

(equatorial paradox) (see also

environmental determinism Environmental determinism (also known as climatic determinism or geographical determinism) is the study of how the physical environment predisposes societies and states towards particular development trajectories. Jared Diamond, Jeffrey Herbst ...

) *

Climatic Regions of India The climate of India consists of a wide range of weather conditions across a vast geographic scale and varied topography. Based on the Köppen climate classification, Köppen system, India hosts six major climate, climatic sub types, ranging ...

* Climatic Research Unit (at the University of East Anglia in the UK) * (climatic zone: see)

clime The climes (singular ''clime''; also ''clima'', plural ''climata'', from Greek κλίμα ''klima'', plural κλίματα ''klimata'', meaning "inclination" or "slope") in classical Greco-Roman geography and astronomy were the divisions of ...

(climatic zone) *

Clinton Foundation The Clinton Foundation (founded in 2001 as the William J. Clinton Presidential Foundation, and renamed in 2013 as the Bill, Hillary & Chelsea Clinton Foundation) is a nonprofit organization under section 501(c)(3) of the U.S. tax code. It was es ...

(see under Clinton Climate Initiative (CCI)) *

cloud In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may ...

cloud albedo Cloud albedo is a measure of the albedo or reflectivity of a cloud. Clouds regulate the amount of solar radiation absorbed by a planet and its solar surface irradiance. Generally, increased cloud cover correlates to a higher albedo and a lower ab ...

("a measure of the reflectivity of a cloud") *

cloud base A cloud base (or the base of the cloud) is the lowest altitude of the visible portion of a cloud. It is traditionally expressed either in metres or feet above mean sea level or above a planetary surface, or as the pressure level corresponding to ...

("the lowest altitude of the visible portion of a cloud") *

cloud chamber A cloud chamber, also known as a Wilson cloud chamber, is a particle detector used for visualizing the passage of ionizing radiation. A cloud chamber consists of a sealed environment containing a supersaturated vapour of water or alcohol. An ...

(Wilson chamber) ("for detecting ... ionizing radiation") *

cloud condensation nuclei Cloud condensation nuclei (CCNs), also known as cloud seeds, are small particles typically 0.2 µm, or one hundredth the size of a cloud droplet. CCNs are a unique subset of aerosols in the atmosphere on which water vapour condenses. This c ...

(CCNs) (see under Phytoplankton role) *

cloud cover Cloud cover (also known as cloudiness, cloudage, or cloud amount) refers to the fraction of the sky obscured by clouds on average when observed from a particular location. Okta is the usual unit for measurement of the cloud cover. The cloud c ...

* cloud feedback *

cloud forcing In meteorology, cloud forcing, cloud radiative forcing (CRF) or cloud radiative effect (CRE) is the difference between the radiation budget components for average cloud conditions and cloud-free conditions. Much of the interest in cloud forcing r ...

(see "greenhouse effect" in paragraph 2) *

cloud forest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud ...

* (cloud formation: see) nephology *

cloud physics Cloud physics is the study of the physical processes that lead to the formation, growth and precipitation of atmospheric clouds. These aerosols are found in the troposphere, stratosphere, and mesosphere, which collectively make up the greatest p ...

cloud seeding Cloud seeding is a type of weather modification that aims to change the amount or type of precipitation that falls from clouds by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysica ...

cloud street Horizontal convective rolls, also known as horizontal roll vortices or cloud streets, are long rolls of counter-rotating air that are oriented approximately parallel to the ground in the planetary boundary layer. Although horizontal convectiv ...

* cloud suck *

cloudburst A cloudburst is an extreme amount of precipitation in a short period of time, sometimes accompanied by hail and thunder, which is capable of creating flood conditions. Cloudbursts can quickly dump large amounts of water, e.g. 25 mm of prec ...

(see "destruction" in paragraph 2 and see "Mumbai" in paragraph 3) *

CloudSat CloudSat is a NASA Earth observation satellite, which was launched on a Delta II rocket on April 28, 2006. It uses radar to measure the altitude and properties of clouds, adding to information on the relationship between clouds and climate in ord ...

("a NASA environmental satellite") *

coefficient of haze The coefficient of haze (also known as smoke shade) is a measurement of visibility interference in the atmosphere. One way to measure this is to draw about 1000 cubic feet of air sample through an air filter and obtain the radiation intensity throu ...

(in meteorology) *

cold-core low A cold-core low, also known as an upper level low or cold-core cyclone, is a cyclone aloft which has an associated cold pool of air residing at high altitude within the Earth's troposphere, without a frontal structure. It is a low pressure syste ...

cold weather boot Bunny boots or Mickey Mouse boots (depending on the version) are the most common nicknames for the Extreme Cold Vapor Barrier Boots (Types I and II) used by the United States Armed Forces. These large, bulbous, waterproof rubber boots can be worn ...

* cold weather rule (cold weather law) (for public utility companies) * (coldest place on earth: see)

climate of Antarctica The climate of Antarctica is the coldest on Earth. The continent is also extremely dry (it is a desert), averaging of precipitation per year. Snow rarely melts on most parts of the continent, and, after being compressed, becomes the glacier ic ...

(see under

Temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...

) *

coldest temperature achieved on Earth The lowest natural temperature ever directly recorded at ground level on Earth is at the then-Soviet Vostok Station in Antarctica on 21 July 1983 by ground measurements. On 10 August 2010, satellite observations showed a surface temperature ...

Colorado low A Colorado low is a low-pressure area that forms in southeastern Colorado or northeastern New Mexico, typically in the winter. After forming, the system moves across the Great Plains. Colorado lows can produce heavy wintry precipitation, and ha ...

Community Climate System Model The Community Climate System Model (CCSM) is a coupled general circulation model (GCM) developed by the University Corporation for Atmospheric Research (UCAR) with funding from the National Science Foundation (NSF), the Department of Energy (DoE), ...

continental climate Continental climates often have a significant annual variation in temperature (warm summers and cold winters). They tend to occur in the middle latitudes (40 to 55 north), within large landmasses where prevailing winds blow overland bringing so ...

contrail Contrails (; short for "condensation trails") or vapor trails are line-shaped clouds produced by aircraft engine exhaust or changes in air pressure, typically at aircraft cruising altitudes several miles above the Earth's surface. Contrails ar ...

controlled airspace Controlled airspace is airspace of defined dimensions within which air traffic control (ATC) services are provided. The level of control varies with different classes of airspace. Controlled airspace usually imposes higher weather minimums tha ...

controlled atmosphere A controlled atmosphere is an agricultural storage method in which the concentrations of oxygen, carbon dioxide and nitrogen, as well as the temperature and humidity of a storage room are regulated. Both dry commodities and fresh fruit and vegetab ...

(for agricultural storage) *

convection Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the c ...

(see under

Atmospheric convection Atmospheric convection is the result of a parcel-environment instability, or temperature difference layer in the atmosphere. Different lapse rates within dry and moist air masses lead to instability. Mixing of air during the day which expands the ...

) *

convective available potential energy In meteorology, convective available potential energy (commonly abbreviated as CAPE), is the integrated amount of work that the upward (positive) buoyancy force would perform on a given mass of air (called an air parcel) if it rose vertically thro ...

(CAPE) (in meteorology) * convective condensation level (CCL) *

convective inhibition Convective inhibition (CIN or CINH) is a numerical measure in meteorology that indicates the amount of energy that will prevent an air parcel from rising from the surface to the level of free convection. CIN is the amount of energy required to o ...

(CIN) *

convective instability In meteorology, convective instability or stability of an air mass refers to its ability to resist vertical motion. A ''stable'' atmosphere makes vertical movement difficult, and small vertical disturbances dampen out and disappear. In an ''uns ...

convective temperature The convective temperature (CT or Tc) is the approximate temperature that air near the surface must reach for cloud formation without mechanical lift. In such case, cloud base begins at the convective condensation level (CCL), whilst with mechanica ...

(T_c) * Cooperative Institute for Atmospheric Sciences and Terrestrial Applications (CIASTA) *

Cooperative Institute for Arctic Research The Cooperative Institute for Arctic Research is designed to be a focal point for interactions between the National Oceanic and Atmospheric Administration (NOAA)/Office of Oceanic and Atmospheric Research (OAR) and the Arctic research community t ...

Cooperative Institute for Climate and Ocean Research A cooperative (also known as co-operative, co-op, or coop) is "an autonomy, autonomous association of persons united voluntarily to meet their common economic, social and cultural needs and aspirations through a jointly owned and democratical ...

(CICOR) *

Cooperative Institute for Climate Applications and Research The Cooperative Institute for Climate Applications and Research (CICAR) was a major collaborative relationship between the National Oceanic and Atmospheric Administration (NOAA) Office of Oceanic and Atmospheric Research (OAR) and Earth Institute, ...

(CICAR) *

Cooperative Institute for Climate Science The Cooperative Institute for Climate Science (CICS) fosters research collaborations between the National Oceanic and Atmospheric Administration (NOAA)/Office of Oceanic and Atmospheric Research (OAR) Geophysical Fluid Dynamics Laboratory (GFDL) a ...

(CICS) *

Cooperative Institute for Limnology and Ecosystems Research The Cooperative Institute for Great Lakes Research, formerly known as the Cooperative Institute for Limnology and Ecosystems Research, fosters research collaborations between the National Oceanic and Atmospheric Administration (NOAA) Office of O ...

(CILER) *

Cooperative Institute for Marine and Atmospheric Studies The Cooperative Institute for Marine and Atmospheric Studies (CIMAS) is a research institute of the University of Miami located in its Rosenstiel School of Marine and Atmospheric Science (RSMAS) in Miami, Florida. CIMAS brings together the Univer ...

(CIMAS) *

Cooperative Institute for Mesoscale Meteorological Studies The Cooperative Institute for Mesoscale Meteorological Studies is a research organization created in 1978 by a cooperative agreement between the University of Oklahoma (OU) and the National Oceanic and Atmospheric Administration (NOAA). CIMMS p ...

(CIMMS) *

Cooperative Institute for Meteorological Satellite Studies __NOTOC__ The Cooperative Institute for Meteorological Satellite Studies (CIMSS) is a research institute where scientists study the use of data from geostationary and polar orbit weather satellites to improve forecasts of weather (including trop ...

(CIMSS) *

Cooperative Institute for Precipitation Systems The Cooperative Institute for Precipitation Systems (CIPS) is a collaborative project headed by Saint Louis University to promote understanding of significant precipitation events. It originally focused on the Midwestern United States but expanded ...

(CIPS) *

Cooperative Institute for Research in Environmental Sciences The Cooperative Institute for Research in Environmental Sciences (CIRES) is a research institute that is sponsored jointly by the National Oceanic and Atmospheric Administration (NOAA) Office of Oceanic and Atmospheric Research (OAR) and the Un ...

(CIRES) *

Cooperative Institute for Research in the Atmosphere The Cooperative Institute for Research in the Atmosphere (CIRA) is a scientific research institution at Colorado State University (CSU) that operates under a cooperative agreement with the National Oceanic and Atmospheric Administration (NOAA) Off ...

(CIRA) *

corona (meteorology) In meteorology, a corona (plural ''coronae'') is an optical phenomenon produced by the diffraction of sunlight or moonlight (or, occasionally, bright starlight or planetlight) by individual small water droplets and sometimes tiny ice crystals o ...

COSMIC Cosmic commonly refers to: * The cosmos, a concept of the universe Cosmic may also refer to: Media * ''Cosmic'' (album), an album by Bazzi * Afro/Cosmic music * "Cosmic", a song by Kylie Minogue from the album '' X'' * CosM.i.C, a member of ...

(Constellation Observing System for Meteorology, Ionosphere, and Climate) * Cosmic Anisotropy Telescope (CAT) *

Cosmic Background Explorer The Cosmic Background Explorer (COBE ), also referred to as Explorer 66, was a NASA satellite dedicated to cosmology, which operated from 1989 to 1993. Its goals were to investigate the cosmic microwave background radiation (CMB or CMBR) of t ...

(COBE) ("to investigate the cosmic background radiation" etc.) *

cosmic microwave background experiments This list is a compilation of experiments measuring the cosmic microwave background (CMB) radiation anisotropies and polarization since the first detection of the CMB by Penzias and Wilson in 1964. There have been a variety of experiments to ...

cosmic microwave background radiation In Big Bang cosmology the cosmic microwave background (CMB, CMBR) is electromagnetic radiation that is a remnant from an early stage of the universe, also known as "relic radiation". The CMB is faint cosmic background radiation filling all space ...

(CMB) (CMBR) (CBR) (MBR) *

cosmic noise Cosmic noise, also known as galactic radio noise, is not actually sound, but a physical phenomenon derived from outside of the Earth's atmosphere. It can be detected through a radio receiver, which is an electronic device that receives radio waves ...

cosmic ray Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own ...

(see under

Lightning Lightning is a naturally occurring electrostatic discharge during which two electrically charged regions, both in the atmosphere or with one on the ground, temporarily neutralize themselves, causing the instantaneous release of an average ...

) * Cosmochemical Periodic Table of the Elements in the Solar System *

cosmochemistry Cosmochemistry (from Greek κόσμος ''kósmos'', "universe" and χημεία ''khemeía'') or chemical cosmology is the study of the chemical composition of matter in the universe and the processes that led to those compositions. This is done ...

cumulonimbus cloud Cumulonimbus (from Latin ''cumulus'', "heaped" and ''nimbus'', "rainstorm") is a dense, towering vertical cloud, typically forming from water vapor condensing in the lower troposphere that builds upward carried by powerful buoyant air currents. ...

(see under Effects) * (cumulonimbus with mammatus: see)

mammatus cloud Mammatus (also called mamma or mammatocumulus, meaning "mammary cloud") is a cellular pattern of pouches hanging underneath the base of a cloud, typically a cumulonimbus raincloud, although they may be attached to other classes of parent cloud ...

* (cumulonimbus with pileus: see) pileus (meteorology) * cumulus castellanus cloud *

cumulus cloud Cumulus clouds are clouds which have flat bases and are often described as "puffy", "cotton-like" or "fluffy" in appearance. Their name derives from the Latin ''cumulo-'', meaning ''heap'' or ''pile''. Cumulus clouds are low-level clouds, gener ...

cumulus congestus cloud Cumulus congestus clouds, also known as towering cumulus, are a form of cumulus that can be based in the low or middle height ranges. They achieve considerable vertical development in areas of deep, moist convection. They are an intermediate stage ...

* cumulus humilis cloud * cumulus mediocris cloud * (cup anemometer: see)

anemometer In meteorology, an anemometer () is a device that measures wind speed and direction. It is a common instrument used in weather stations. The earliest known description of an anemometer was by Italian architect and author Leon Battista Alberti ...

(see under Cup anemometers) * current solar income *

cyclogenesis Cyclogenesis is the development or strengthening of cyclonic circulation in the atmosphere (a low-pressure area). Cyclogenesis is an umbrella term for at least three different processes, all of which result in the development of some sort of cycl ...

cyclone In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an an ...

cyclone furnace A cyclone furnace is a type of coal combustor commonly used in large industrial boilers. Background Developed in the early 1942 by Babcock & Wilcox to take advantage of coal grades not suitable for pulverized coal combustion, cyclone furnaces fee ...

(a type of coal combustor) * (cyclone preparedness: see)

hurricane preparedness Cyclone mitigation encompasses the actions and planning taken before a tropical cyclone strikes to mitigate damage and injury from the storm. Knowledge of tropical cyclone impacts on an area help plan for future possibilities. Preparedness ma ...

cyclonic separation Cyclonic separation is a method of removing particulates from an air, gas or liquid stream, without the use of filters, through vortex separation. When removing particulate matter from liquid, a hydrocyclone is used; while from gas, a gas cyclone ...

(method of removing particles from an air or gas stream)

D

* D region (in the atmosphere) *

Darrieus wind turbine The Darrieus wind turbine is a type of vertical axis wind turbine (VAWT) used to generate electricity from wind energy. The turbine consists of a number of curved aerofoil blades mounted on a rotating shaft or framework. The curvature of the bla ...

dawn Dawn is the time that marks the beginning of twilight before sunrise. It is recognized by the appearance of indirect sunlight being scattered in Earth's atmosphere, when the centre of the Sun's disc has reached 18° below the observer's horizo ...

dBZ (meteorology) dBZ stands for '' decibel relative to Z''. It is a logarithmic dimensionless technical unit used in radar, mostly in weather radar, to compare the equivalent reflectivity factor (Z) of a remote object (in mm6 per m3) to the return of a dropl ...

degree (temperature) The term ''degree'' is used in several scales of temperature, with the notable exception of kelvin, primary unit of temperature for engineering and the physical sciences. The degree symbol ° is usually used, followed by the initial letter of the u ...

deicing Deicing is the process of removing snow, ice or frost from a surface. Anti-icing is the application of chemicals that not only deice but also remain on a surface and continue to delay the reformation of ice for a certain period of time, or preve ...

dendroclimatology Dendroclimatology is the science of determining past climates from trees (primarily properties of the annual tree rings). Tree rings are wider when conditions favor growth, narrower when times are difficult. Other properties of the annual rings, s ...

("extracting past climate information from information in trees") *

density altitude The density altitude is the altitude relative to standard atmospheric conditions at which the air density would be equal to the indicated air density at the place of observation. In other words, the density altitude is the air density given as ...

Denver Convergence Vorticity Zone The Denver Convergence Vorticity Zone (DCVZ) is an orographically-induced atmospheric phenomenon characterized by convergent winds in the High Plains just east of the Denver metropolitan area, typically in length and oriented in a north-south dir ...

(DCVZ) *

deposition (physics) Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase. Deposition is a thermodynamic process. The reverse of deposition is sublimation and hence sometimes deposition is called desublimat ...

* (depression eteorology see)

low pressure area In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible ...

derecho A ''derecho'' (, from es, derecho, link=no , 'straight') is a widespread, long-lived, straight-line wind storm that is associated with a fast-moving group of severe thunderstorms known as a mesoscale convective system. Derechos can cause hurri ...

(see also

List of derecho events The following is a list of derecho events. North America Europe South America Asia See also * Bow echo * Line echo wave pattern * List of deadliest Storm Prediction Center days by outlook risk level * List of microbursts * L ...

) *

dew Dew is water in the form of droplets that appears on thin, exposed objects in the morning or evening due to condensation. As the exposed surface cools by radiating its heat, atmospheric moisture condenses at a rate greater than that at wh ...

dew point The dew point is the temperature to which air must be cooled to become saturated with water vapor, assuming constant air pressure and water content. When cooled below the dew point, moisture capacity is reduced and airborne water vapor will cond ...

(dewpoint, T_d) *

dew point depression The dew point depression (T-Td) is the difference between the temperature and dew point temperature at a certain height in the atmosphere. For a constant temperature, the smaller the difference, the more moisture there is, and the higher the rela ...

disdrometer A disdrometer is an instrument used to measure the drop size distribution and velocity of falling hydrometeors. Some disdrometers can distinguish between rain, graupel, and hail. The uses for disdrometers are numerous. They can be used for ...

downwelling Downwelling is the process of accumulation and sinking of higher density material beneath lower density material, such as cold or saline water beneath warmer or fresher water or cold air beneath warm air. It is the ''sinking'' limb of a convecti ...

drizzle Drizzle is a light precipitation consisting of liquid water drops smaller than those of rain – generally smaller than in diameter. Drizzle is normally produced by low stratiform clouds and stratocumulus clouds. Precipitation rates from dri ...

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

dry-bulb temperature The dry-bulb temperature (DBT) is the temperature of air measured by a thermometer freely exposed to the air, but shielded from radiation and moisture. DBT is the temperature that is usually thought of as air temperature, and it is the true ther ...

dry line A dry line (also called a dew point line, or Marfa front, after Marfa, Texas) is a line across a continent that separates moist air and dry air. One of the most prominent examples of such a separation occurs in central North America, especially T ...

(dew point line) * dry punch *

dry season The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The te ...

dusk Dusk occurs at the darkest stage of twilight, or at the very end of astronomical twilight after sunset and just before nightfall.''The Random House College Dictionary'', "dusk". At predusk, during early to intermediate stages of twilight, enou ...

E

Earth's atmosphere The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for ...

Earth's magnetic field Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic f ...

Earth System Research Laboratory The Earth System Research Laboratories (ESRL) is an alliance of four NOAA scientific labs, all located in the David Skaggs Research Center on the Department of Commerce campus in Boulder, Colorado. Organized under NOAA’s Office of Oceanic and ...

(ESRL) *

economics of global warming The economics of climate change concerns the economic aspects of climate change; this can inform policies that governments might consider in response. A number of factors make this and the politics of climate change a difficult problem: it is a l ...

Emagram An emagram is one of four thermodynamic diagrams used to display temperature lapse rate and moisture content profiles in the atmosphere. The emagram has axes of temperature (T) and pressure (p). In the emagram, the dry adiabats make an angle of a ...

effect of Hurricane Katrina on New Orleans As the center of Hurricane Katrina passed southeast of New Orleans on August 29, 2005, winds downtown were in the Category 1 range with frequent intense gusts. The storm surge caused approximately 23 breaches in the drainage canal and navi ...

(see also

Hurricane Katrina effects by region The article covers the Hurricane Katrina effects by region, within the United States and Canada. The effects of ''Hurricane Katrina'', in late August 2005, were catastrophic and widespread. It was one of the deadliest natural disasters in U.S. hi ...

) *

effect of sun angle on climate The amount of heat energy received at any location on the globe is a direct effect of Sun angle on climate, as the angle at which sunlight strikes Earth varies by location, time of day, and season due to Earth's orbit around the Sun and Earth's r ...

Enhanced Fujita scale The Enhanced Fujita scale (abbreviated as EF-Scale) rates tornado intensity based on the severity of the damage they cause. It is used in some countries, including the United States, Canada, China, and Mongolia. The Enhanced Fujita scale repla ...

(EF scale) *

eolian processes Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit materials ...

equator The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can als ...

(see under Equatorial seasons and climate) *

equilibrium level In meteorology, the equilibrium level (EL), or level of neutral buoyancy (LNB), or limit of convection (LOC), is the height at which a rising parcel of air is at the same temperature as its environment. This means that unstable air is now stable ...

(EL) * equivalent potential temperaturбe *

equivalent temperature In atmospheric science, equivalent temperature is the temperature of air in a parcel from which all the water vapor has been extracted by an adiabatic process. Air contains water vapor that has been evaporated into it from liquid sources (lake ...

European Centre for Medium-Range Weather Forecasts The European Centre for Medium-Range Weather Forecasts (ECMWF) is an independent intergovernmental organisation supported by most of the nations of Europe. It is based at three sites: Shinfield Park, Reading, United Kingdom; Bologna, Italy; an ...

(ECMWF) *

European Climate Change Programme The European Climate Change Programme (ECCP) was launched in June 2000 by the European Union's European Commission, with the purpose of avoiding dangerous climate change. The goal of the ECCP is to identify, develop and implement all the necessary ...

(ECCP) *

European emission standards The European emission standards are vehicle emission standards for pollution from the use of new land surface vehicles sold in the European Union and EEA member states and the UK, and ships in EU waters. The standards are defined in a ser ...

(for motor vehicles) *

European Severe Storms Laboratory The European Severe Storms Laboratory (ESSL) is a scientific organisation that conducts research on severe convective storms, tornadoes, intense precipitation events, and avalanches across Europe and the Mediterranean. It operates the widely con ...

(ESSL) *

European windstorm European windstorms are powerful extratropical cyclones which form as cyclonic windstorms associated with areas of low atmospheric pressure. They can occur throughout the year, but are most frequent between October and March, with peak intensit ...

evaporation Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidi ...

evaporative cooler An evaporative cooler (also known as evaporative air conditioner, swamp cooler, swamp box, desert cooler and wet air cooler) is a device that cools air through the evaporation of water. Evaporative cooling differs from other air conditioning s ...

evaporative cooling An evaporative cooler (also known as evaporative air conditioner, swamp cooler, swamp box, desert cooler and wet air cooler) is a device that cools air through the evaporation of water. Evaporative cooling differs from other air conditioning sy ...

evaporite An evaporite () is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocea ...

(a mineral sediment resulting from evaporation of saline water) *

evapotranspiration Evapotranspiration (ET) is the combined processes by which water moves from the earth’s surface into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpi ...

(ET) (sum of evaporation and plant transpiration) *

exhaust gas recirculation In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide () emissions reduction technique used in petrol/gasoline, diesel engines and some hydrogen engines. EGR works by recirculating a portion of an engine's exhaust ...

(EGR) (exhaust gas recycling) *

exosphere The exosphere ( grc, ἔξω "outside, external, beyond", grc, σφαῖρα "sphere") is a thin, atmosphere-like volume surrounding a planet or natural satellite where molecules are gravitationally bound to that body, but where the densit ...

(layer of atmosphere) *

extratropical cyclone Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of ...

(mid-latitude cyclone) *

extreme weather Extreme weather or extreme climate events includes unexpected, unusual, severe, or unseasonal weather; weather at the extremes of the historical distribution—the range that has been seen in the past. Often, extreme events are based on a locat ...

extremes on Earth This article lists extreme locations on Earth that hold geographical records or are otherwise known for their geophysical or meteorological superlatives. All of these locations are Earth-wide extremes; extremes of individual continents or coun ...

F

fire whirl A fire whirl or fire devil (sometimes referred to as a fire tornado) is a whirlwind induced by a fire and often (at least partially) composed of flame or ash. These start with a whirl of wind, often made visible by smoke, and may occur when inte ...

firestorm A firestorm is a conflagration which attains such intensity that it creates and sustains its own wind system. It is most commonly a natural phenomenon, created during some of the largest bushfires and wildfires. Although the term has been used ...

fog Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Reprint from Fog can be considered a type of low-lying cloud usually resembling stratus, and is heavily influ ...

forensic meteorology Forensic meteorology is meteorology, the scientific study of weather, applied to the process of reconstructing weather events for a certain time and location. This is done by acquiring and analyzing local weather reports such as surface observations ...

free convective layer In atmospheric sciences, the free convective layer (FCL) is the layer of conditional or potential instability in the troposphere. It is a layer in which rising air can experience positive buoyancy (PBE) so that deep, moist convection (DMC) can occ ...

(FCL) *

freezing rain Freezing rain is rain maintained at temperatures below freezing by the ambient air mass that causes freezing on contact with surfaces. Unlike a mixture of rain and snow or ice pellets, freezing rain is made entirely of liquid droplets. The raind ...

* (front eteorology see)

surface weather analysis Surface weather analysis is a special type of weather map that provides a view of weather elements over a geographical area at a specified time based on information from ground-based weather stations. Weather maps are created by plotting or tra ...

frontogenesis Frontogenesis is a meteorological process of tightening of horizontal temperature gradients to produce fronts. In the end, two types of fronts form: cold fronts and warm fronts. A cold front is a narrow line where temperature decreases rapidly. A ...

frontolysis Frontolysis in meteorology, is the dissipation or weakening of an atmospheric front. In contrary to areas of "Frontogenesis", the areas where air masses diverge are called areas of frontolysis. See also *Frontogenesis *Outflow boundary Reference ...

frost Frost is a thin layer of ice on a solid surface, which forms from water vapor in an above-freezing atmosphere coming in contact with a solid surface whose temperature is below freezing, and resulting in a phase change from water vapor (a gas) ...

frost creep Frost heaving (or a frost heave) is an upwards swelling of soil during freezing conditions caused by an increasing presence of ice as it grows towards the surface, upwards from the depth in the soil where freezing temperatures have penetrated int ...

(frost heave) *

frost flowers A frost flower or ice flower is formed when thin layers of ice are extruded from long-stemmed plants in autumn or early winter. The thin layers of ice are often formed into exquisite patterns that curl into "petals" that resemble flowers. Typ ...

(frost castles) (ice castles) (ice ribbons) (ice blossoms) *

frost heaving Frost heaving (or a frost heave) is an upwards swelling of soil during freezing conditions caused by an increasing presence of ice as it grows towards the surface, upwards from the depth in the soil where freezing temperatures have penetrated int ...

(frost heave) *

frost law Frost laws are seasonal restrictions on traffic weight limits and speeds on roadways subject to thaw weakening. In climates that experience below-freezing temperatures, damage to roads from thaw-weakening have led to many US states, Canadian provin ...

frost line The frost line—also known as frost depth or freezing depth—is most commonly the depth to which the groundwater in soil is expected to freeze. The frost depth depends on the climatic conditions of an area, the heat transfer properties of the s ...

* (frost point: see)

(dewpoint) *

frostbite Frostbite is a skin injury that occurs when exposed to extreme low temperatures, causing the freezing of the skin or other tissues, commonly affecting the fingers, toes, nose, ears, cheeks and chin areas. Most often, frostbite occurs in the han ...

Fujita scale The Fujita scale (F-Scale; ), or Fujita–Pearson scale (FPP scale), is a scale for rating tornado intensity, based primarily on the damage tornadoes inflict on human-built structures and vegetation. The official Fujita scale category is determ ...

(F scale) (for measuring tornadoes) *

fulgurite Fulgurites (), commonly known as "fossilized lightning", are natural tubes, clumps, or masses of sintered, vitrified, and/or fused soil, sand, rock, organic debris and other sediments that sometimes form when lightning discharges into ground. ...

* (full lunar eclipse: see)

lunar eclipse A lunar eclipse occurs when the Moon moves into the Earth's shadow. Such alignment occurs during an eclipse season, approximately every six months, during the full moon phase, when the Moon's orbital plane is closest to the plane of the Earth ...

full-spectrum Full-spectrum light is light that covers the electromagnetic spectrum from infrared to near-ultraviolet, or all wavelengths that are useful to plant or animal life; in particular, sunlight is considered full spectrum, even though the solar spectral ...

light *

funnel cloud A funnel cloud is a funnel-shaped cloud of condensed water droplets, associated with a rotating column of wind and extending from the base of a cloud (usually a cumulonimbus or towering cumulus cloud) but not reaching the ground or a water su ...

(related to a tornado)

G

galactic cosmic ray Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own ...

(GCR) *

gale A gale is a strong wind; the word is typically used as a descriptor in nautical contexts. The U.S. National Weather Service defines a gale as sustained surface winds moving at a speed of between 34 and 47 knots (, or ).gale warning A gale warning is an alert issued by national weather forecasting agencies around the world in an event that maritime locations currently or imminently experiencing winds of gale force on the Beaufort scale. Gale warnings (and gale watches) a ...

Galileo thermometer A Galileo thermometer (or Galilean thermometer) is a thermometer made of a sealed glass cylinder containing a clear liquid and several glass vessels of varying density. The individual floats rise or fall in proportion to their respective density ...

(Galilean thermometer) *

Galveston, Texas Galveston ( ) is a coastal resort city and port off the Southeast Texas coast on Galveston Island and Pelican Island in the U.S. state of Texas. The community of , with a population of 47,743 in 2010, is the county seat of surrounding Galvesto ...

(see under Hurricane of 1900 and recovery) *

Galveston Hurricane of 1900 Galveston ( ) is a coastal resort city and port off the Southeast Texas coast on Galveston Island and Pelican Island in the U.S. state of Texas. The community of , with a population of 47,743 in 2010, is the county seat of surrounding Galvesto ...

(in the US) *

gas balloon A gas balloon is a balloon that rises and floats in the air because it is filled with a gas lighter than air (such as helium or hydrogen). When not in flight, it is tethered to prevent it from flying away and is sealed at the bottom to prevent t ...

(see under

History History (derived ) is the systematic study and the documentation of the human activity. The time period of event before the History of writing#Inventions of writing, invention of writing systems is considered prehistory. "History" is an umbr ...

) *

gas flare A gas flare, alternatively known as a flare stack, flare boom, ground flare, or flare pit is a gas combustion device used in places such as petroleum refineries, chemical plants and natural gas processing plants, oil or gas extraction sites havin ...

(flare stack) * (gas warfare: see)

chemical warfare Chemical warfare (CW) involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from nuclear warfare, biological warfare and radiological warfare, which together make up CBRN, the military acronym ...

Geophysical Fluid Dynamics Laboratory The Geophysical Fluid Dynamics Laboratory (GFDL) is a laboratory in the National Oceanic and Atmospheric Administration (NOAA) Office of Oceanic and Atmospheric Research (OAR). The current director is Dr. Venkatachalam Ramaswamy. It is one of se ...

(GFDL) *

glossary of climate change This glossary of climate change is a list of definitions of terms and concepts relevant to climate change, global warming, and related topics. 0–9 A B C ...

* glossary of environmental science *

glossary of tornado terms The following is a glossary of tornado terms. It includes scientific as well as selected informal terminology. A * ''Advanced Radar Research Center'' (ARRC) - * ''Advection'' - * ''Air parcel'' - * ''American Geophysical Union'' (AGU) - * ...

glossary of tropical cyclone terms The following is a glossary of tropical cyclone terms. A ;Advisory: Official information issued by tropical cyclone warning centers describing all tropical cyclone watches and warnings in effect along with details concerning tropical cyclone loc ...

glossary of wildfire terms This glossary of wildfire terms is a list of definitions of terms and concepts relevant to wildfires and wildland firefighting. Except where noted, terms have largely been sourced from a 1998 Fireline Handbook transcribed for a Conflict 21 count ...

gustnado A gustnado is a brief, shallow surface-based vortex which forms within the downburst emanating from a thunderstorm. The name is a portmanteau by elision of "gust front tornado", as gustnadoes form due to non-tornadic straight-line wind feature ...

Ge-Gk

geomagnetic storm A geomagnetic storm, also known as a magnetic storm, is a temporary disturbance of the Earth's magnetosphere caused by a solar wind shock wave and/or cloud of magnetic field that interacts with the Earth's magnetic field. The disturbance that d ...

* (geomagnetism: see)

* geospatial technology (Spatial Information Technology) *

Geostationary Operational Environmental Satellite The Geostationary Operational Environmental Satellite (GOES), operated by the United States' National Oceanic and Atmospheric Administration (NOAA)'s National Environmental Satellite, Data, and Information Service division, supports weather for ...

(GOES) (a program of the US) *

geostatistics Geostatistics is a branch of statistics focusing on spatial or spatiotemporal datasets. Developed originally to predict probability distributions of ore grades for mining operations, it is currently applied in diverse disciplines including petro ...

geostrophic wind In atmospheric science, geostrophic flow () is the theoretical wind that would result from an exact balance between the Coriolis force and the pressure gradient force. This condition is called '' geostrophic equilibrium'' or ''geostrophic balanc ...

Global Atmosphere Watch The Global Atmosphere Watch (GAW) is a worldwide system established by the World Meteorological Organizationa United Nations agencyto monitor trends in the Earth's atmosphere. It arose out of concerns for the state of the atmosphere in the 1960s. ...

(GAW) *

Global Forecast System The Global Forecast System (GFS) is a global numerical weather prediction system containing a global computer model and variational analysis run by the United States' National Weather Service (NWS). Operation The mathematical model is run f ...

(GFS) *

greenhouse effect The greenhouse effect is a process that occurs when energy from a planet's host star goes through the planet's atmosphere and heats the planet's surface, but greenhouse gases in the atmosphere prevent some of the heat from returning directly ...

greenhouse gas A greenhouse gas (GHG or GhG) is a gas that Absorption (electromagnetic radiation), absorbs and Emission (electromagnetic radiation), emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse ...

(GHG) *

growing degree day Growing degree days (GDD), also called growing degree units (GDUs), are a heuristic tool in phenology. GDD are a measure of heat accumulation used by horticulturists, gardeners, and farmers to predict plant and animal development rates such as the ...

(GDD) *

growing season A season is a division of the year marked by changes in weather, ecology, and the amount of daylight. The growing season is that portion of the year in which local conditions (i.e. rainfall, temperature, daylight) permit normal plant growth. Whil ...

gust front An outflow boundary, also known as a gust front, is a storm-scale or mesoscale boundary separating thunderstorm-cooled air (outflow) from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually a ...

H

hail Hail is a form of solid precipitation. It is distinct from ice pellets (American English "sleet"), though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailstone. Ice pellets generally fal ...

halo (optical phenomenon) A halo is an optical phenomenon produced by light (typically from the Sun or Moon) interacting with ice crystals suspended in the atmosphere. Halos can have many forms, ranging from colored or white rings to arcs and spots in the sky. Many o ...

haze Haze is traditionally an atmospheric phenomenon in which dust, smoke, and other dry particulates suspended in air obscure visibility and the clarity of the sky. The World Meteorological Organization manual of codes includes a classification ...

heat In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is al ...

* (heat budget: see)

radiation budget Earth's energy budget accounts for the balance between the energy that Earth receives from the Sun and the energy the Earth loses back into outer space. Smaller energy sources, such as Earth's internal heat, are taken into consideration, but m ...

* (heat equator: see)

thermal equator The thermal equator (also known as "the heat equator") is a belt encircling Earth, defined by the set of locations having the highest mean annual temperature at each longitude around the globe. Because local temperatures are sensitive to the geogr ...

* (heat lightning: see)

lightning Lightning is a naturally occurring electrostatic discharge during which two electric charge, electrically charged regions, both in the atmosphere or with one on the land, ground, temporarily neutralize themselves, causing the instantaneous ...

heat wave A heat wave, or heatwave, is a period of excessively hot weather, which may be accompanied by high humidity, especially in oceanic climate countries. While definitions vary, a heat wave is usually measured relative to the usual climate in the ...

heating degree day Heating degree day (HDD) is a measurement designed to quantify the demand for energy needed to heat a building. HDD is derived from measurements of outside air temperature. The heating requirements for a given Architectural structure, building at ...

(HDD) * (Heaviside layer)

Kennelly–Heaviside layer The Heaviside layer, sometimes called the Kennelly–Heaviside layer, named after Arthur E. Kennelly and Oliver Heaviside, is a layer of ionised gas occurring roughly between 90km and 150 km (56 and 93 mi) above the ground — one o ...

(E region) (in the atmosphere) *

Heavy snow warning A heavy snow warning was a hazardous weather statement issued by the Weather Forecast Offices of the National Weather Service (NWS) in the United States which indicates a high rate of snowfall was occurring or was forecast to occur. Generally, th ...

heliostat A heliostat (from ''helios'', the Greek word for ''sun'', and ''stat'', as in stationary) is a device that includes a mirror, usually a plane mirror, which turns so as to keep reflecting sunlight toward a predetermined target, compensating ...

High Frequency Active Auroral Research Program The High-frequency Active Auroral Research Program (HAARP) was initiated as an ionospheric research program jointly funded by the U.S. Air Force, the U.S. Navy, the University of Alaska Fairbanks, and the Defense Advanced Research Projects Age ...

(HAARP) *

high pressure area A high-pressure area, high, or anticyclone, is an area near the surface of a planet where the atmospheric pressure is greater than the pressure in the surrounding regions. Highs are middle-scale meteorological features that result from interpl ...

High Resolution Fly's Eye Cosmic Ray Detector The High Resolution Fly's Eye or HiRes detector was an ultra-high-energy cosmic ray observatory that operated in the western Utah desert from May 1997 until April 2006. HiRes used the atmospheric fluorescence technique that was pioneered ...

high-altitude airship Atmospheric satellite (United States usage, abbreviated atmosat) or pseudo-satellite (British usage) is a marketing term for an aircraft that operates in the atmosphere at high altitudes for extended periods of time, in order to provide servic ...

(HAA) *

hodograph A hodograph is a diagram that gives a vectorial visual representation of the movement of a body or a fluid. It is the locus of one end of a variable vector, with the other end fixed. The position of any plotted data on such a diagram is propor ...

humid continental climate A humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900, typified by four distinct seasons and large seasonal temperature differences, with warm to hot (and often humid) summers and freezing ...

humid subtropical climate A humid subtropical climate is a zone of climate characterized by hot and humid summers, and cool to mild winters. These climates normally lie on the southeast side of all continents (except Antarctica), generally between latitudes 25° and 40° ...

* (humidex)

heat index The heat index (HI) is an index that combines air temperature and relative humidity, in shaded areas, to posit a human-perceived equivalent temperature, as how hot it would feel if the humidity were some other value in the shade. The result is als ...

(HI) *

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depe ...

HurriQuake The HurriQuake nail is a construction nail designed by Ed Sutt for Bostitch, a division of Stanley Works, and patented in 2004. The features of the nail are designed primarily to provide more structural integrity for a building, especially agains ...

nail (for resisting hurricanes and earthquakes) * (hydrologic cycle)

water cycle The water cycle, also known as the hydrologic cycle or the hydrological cycle, is a biogeochemical cycle that describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly cons ...

* hydrological phenomenon *

hydrology Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and environmental watershed sustainability. A practitioner of hydrology is calle ...

hydrosphere The hydrosphere () is the combined mass of water found on, under, and above the surface of a planet, minor planet, or natural satellite. Although Earth's hydrosphere has been around for about 4 billion years, it continues to change in shape. This ...

hygrometer A hair tension dial hygrometer with a nonlinear scale. A hygrometer is an instrument used to measure the amount of water vapor in air, in soil, or in confined spaces. Humidity measurement instruments usually rely on measurements of some other qu ...

(different from

hydrometer A hydrometer or lactometer is an instrument used for measuring density or relative density of liquids based on the concept of buoyancy. They are typically calibrated and graduated with one or more scales such as specific gravity. A hydrometer ...

) *

hypercane A hypercane is a hypothetical class of extreme tropical cyclone that could form if sea surface temperatures reached approximately , which is warmer than the warmest ocean temperature ever recorded. Such an increase could be caused by a large ast ...

("hypothetical class of hurricane")

I

ice Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaq ...

* Ice Accretion Indicator *

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

ice storm An ice storm, also known as a glaze event or a silver storm is a type of winter storm characterized by freezing rain. The U.S. National Weather Service defines an ice storm as a storm which results in the accumulation of at least of ice on ex ...

Ice Storm Warning An ice storm warning is a hazardous weather statement issued by the Weather Forecast Offices of the National Weather Service in the United States which indicates that freezing rain produces a significant and possibly damaging accumulation of ice ...

illuminance In photometry, illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness ...

impact winter An impact winter is a hypothesized period of prolonged cold weather due to the impact of a large asteroid or comet on the Earth's surface. If an asteroid were to strike land or a shallow body of water, it would eject an enormous amount of dust, ...

impluvium The ''impluvium'' (pl. ''impluvia'') is a water-catchment pool system meant to capture rain-water flowing from the ''compluvium'', or slanted roof. Often placed "inside", instead of "outside", a building, it is a notable feature in many archite ...

in situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...

(see under Earth and atmospheric sciences) * incidental radiator *

India Meteorological Department The India Meteorological Department (IMD) is an agency of the Ministry of Earth Sciences of the Government of India. It is the principal agency responsible for meteorological observations, weather forecasting and seismology. IMD is headquarter ...

Indian summer An Indian summer is a period of unseasonably warm, dry weather that sometimes occurs in autumn in temperate regions of the northern hemisphere. Several sources describe a true Indian summer as not occurring until after the first frost, or more s ...

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

(IR) radiation (see under

Meteorology Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did not ...

) *

insolation Solar irradiance is the power per unit area (surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument. Solar irradiance is measured in watts per square metre (W/m ...

instrument meteorological conditions In aviation, instrument meteorological conditions (IMC) is a METAR, flight category that describes weather conditions that require pilots to fly primarily by reference to Flight instruments, instruments, and therefore under instrument flight rule ...

(IMG) *

instrumental temperature record The instrumental temperature record is a record of temperatures within Earth's climate based on direct, instrument-based measurements of air temperature and ocean temperature. Instrumental temperature records are distinguished from indirect rec ...

* intentional radiator *

International Meteorological Organization The International Meteorological Organization (IMO; 1873–1951) was the first organization formed with the purpose of exchanging weather information among the countries of the world. It came into existence from the realization that weather systems ...

(IMO) *

International Temperature Scale of 1990 The International Temperature Scale of 1990 (ITS-90) is an equipment calibration standard specified by the International Committee of Weights and Measures (CIPM) for making measurements on the Kelvin and Celsius temperature scales. It is an appro ...

(ITS-90) *

International Terrestrial Reference System The International Terrestrial Reference System (ITRS) describes procedures for creating reference frames suitable for use with measurements on or near the Earth's surface. This is done in much the same way that a physical standard might be descri ...

(ITRS) *

inversion Inversion or inversions may refer to: Arts * , a French gay magazine (1924/1925) * ''Inversion'' (artwork), a 2005 temporary sculpture in Houston, Texas * Inversion (music), a term with various meanings in music theory and musical set theory * ...

Invest (meteorology) An invest in meteorology (short for ''investigative area'', alternatively written INVEST) is a designated area of disturbed weather that is being monitored for potential tropical cyclone development. Invests are designated by three separate United ...

* ion wind (ion wind) (coronal wind) *

ionosonde An ionosonde, or chirpsounder, is a special radar for the examination of the ionosphere. The basic ionosonde technology was invented in 1925 by Gregory Breit and Merle A. Tuve and further developed in the late 1920s by a number of prominent phys ...

(chirpsounder) *

ionosphere The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an ...

ionospheric reflection In radio communication, skywave or skip refers to the propagation of radio waves reflected or refracted back toward Earth from the ionosphere, an electrically charged layer of the upper atmosphere. Since it is not limited by the curvature ...

ionospheric sounding In telecommunication and radio science, an ionospheric sounding is a technique that provides real-time data on high-frequency ionospheric-dependent radio propagation, using a basic system consisting of a synchronized transmitter and receiver. T ...

iron cycle The iron cycle (Fe) is the biogeochemical cycle of iron through the atmosphere, hydrosphere, biosphere and lithosphere. While Fe is highly abundant in the Earth's crust, it is less common in oxygenated surface waters. Iron is a key micronutrient i ...

irradiance In radiometry, irradiance is the radiant flux ''received'' by a ''surface'' per unit area. The SI unit of irradiance is the watt per square metre (W⋅m−2). The CGS unit erg per square centimetre per second (erg⋅cm−2⋅s−1) is often used ...

irradiation Irradiation is the process by which an object is exposed to radiation. The exposure can originate from various sources, including natural sources. Most frequently the term refers to ionizing radiation, and to a level of radiation that will serve ...

* isobar * isochore (in a

thermodynamic Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of ther ...

diagram) *

isodrosotherm A contour line (also isoline, isopleth, or isarithm) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensional graph ...

* isogon (meteorology) * (isogram)

contour line A contour line (also isoline, isopleth, or isarithm) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensional grap ...

(

level set In mathematics, a level set of a real-valued function of real variables is a set where the function takes on a given constant value , that is: : L_c(f) = \left\~, When the number of independent variables is two, a level set is calle ...

) (isarithm) * isohel * isohume *

isohyet A contour line (also isoline, isopleth, or isarithm) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensional grap ...

* isohypse (in

topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...

) * isotherm

K

katabatic wind A katabatic wind (named from the Greek word κατάβασις ''katabasis'', meaning "descending") is a drainage wind, a wind that carries high-density air from a higher elevation down a slope under the force of gravity. Such winds are sometim ...

L

Laboratory for Atmospheric and Space Physics The Laboratory for Atmospheric and Space Physics (LASP) is a research organization at the University of Colorado Boulder. LASP is a research institute with over one hundred research scientists ranging in fields from solar influences, to Earth' ...

(LASP) *

lake effect snow Lake-effect snow is produced during cooler atmospheric conditions when a cold air mass moves across long expanses of warmer lake water. The lower layer of air, heated up by the lake water, picks up water vapor from the lake and rises up through ...

(a snowsquall) * (lake surge: see)

storm surge A storm surge, storm flood, tidal surge, or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low-pressure weather systems, such as cyclones. It is measured as the rise in water level above the n ...

land hemisphere The land hemisphere and water hemisphere are the hemispheres of Earth containing the largest possible total areas of land and ocean, respectively. By definition (assuming that the entire surface can be classed as either "land" or "ocean"), the t ...

land lighthouse A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lens (optics), lenses and to serve as a beacon for navigational aid, for maritime pilots at sea or on inland waterways. L ...

landspout __NOTOC__ Landspout is a term created by atmospheric scientist Howard B. Bluestein in 1985 for a kind of tornado not associated with a mesocyclone. The ''Glossary of Meteorology'' defines a landspout as : "Colloquial expression describing tor ...

lapse rate The lapse rate is the rate at which an atmospheric variable, normally temperature in Earth's atmosphere, falls with altitude. ''Lapse rate'' arises from the word ''lapse'', in the sense of a gradual fall. In dry air, the adiabatic lapse rate is ...

Lemon technique The Lemon technique is a method used by meteorologists using weather radar to determine the relative strength of thunderstorm cells in a vertically wind shear, sheared environment. It is named for Leslie R. Lemon, the co-creator of the current conce ...

lenticular cloud Lenticular clouds (Latin: ''Lenticularis'' lentil-shaped, from ''lenticula'' lentil) are stationary clouds that form mostly in the troposphere, typically in parallel alignment to the wind direction. They are often comparable in appearance to a ...

level of free convection The level of free convection (LFC) is the altitude in the atmosphere where an air parcel lifted adiabatically until saturation becomes warmer than the environment at the same level, so that positive buoyancy can initiate self-sustained convection. ...

(LFC) *

life zone The life zone concept was developed by C. Hart Merriam in 1889 as a means of describing areas with similar plant and animal communities. Merriam observed that the changes in these communities with an increase in latitude at a constant elevation ar ...

lifted condensation level The lifted condensation level or lifting condensation level (LCL) is formally defined as the height at which the relative humidity (RH) of an air parcel will reach 100% with respect to liquid water when it is cooled by dry adiabatic lifting. The ...

(LCL) *

lifted index The lifted index (LI) is the temperature difference between the environment Te(p) and an air parcel lifted adiabatically Tp(p) at a given pressure height in the troposphere (lowest layer where most weather occurs) of the atmosphere, usually 500 ...

(LI) *

lightning detection A lightning detector is a device that detects lightning produced by thunderstorms. There are three primary types of detectors: ''ground-based'' systems using multiple antennas, ''mobile systems'' using a direction and a sense antenna in the same l ...

lightning prediction system A lightning prediction system is a type of Lightning detection, lightning detection equipment that determines when atmospheric conditions likely to produce lightning strikes and sounds an alarm, warning those nearby that lightning is imminent and ...

lightning rod A lightning rod or lightning conductor (British English) is a metal rod mounted on a structure and intended to protect the structure from a lightning strike. If lightning hits the structure, it will preferentially strike the rod and be conducte ...

(lightning protector) (lightning finial) *

lightning safety A lightning strike or lightning bolt is an electric discharge between the atmosphere and the ground. Most originate in a cumulonimbus cloud and terminate on the ground, called cloud-to-ground (CG) lightning. A less common type of strike, ground- ...

* (lightning storm)

thunderstorm A thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder. Relatively weak thunderstorms are someti ...

(T-storm) (electrical storm) *

lightvessel A lightvessel, or lightship, is a ship that acts as a lighthouse. They are used in waters that are too deep or otherwise unsuitable for lighthouse construction. Although some records exist of fire beacons being placed on ships in Roman times, t ...

(lightship) *

line echo wave pattern A line echo wave pattern (LEWP) is a weather radar formation in which a single line of thunderstorms presenting multiple bow echoes forms south (or equatorward) of a mesoscale low-pressure area with a rotating "head". LEWP often are associated wi ...

(LEWP) *

line source A line source, as opposed to a point source, area source, or volume source, is a source of air, noise, water contamination or electromagnetic radiation that emanates from a linear (one-dimensional) geometry. The most prominent linear sources a ...

("a source of air, noise, water contamination or electromagnetic radiation") * (list of all-time high and low temperatures by state: see) U.S. state temperature extremes * list of basic earth science topics *

list of Category 5 Atlantic hurricanes A Category 5 Atlantic hurricane is a tropical cyclone that reaches Category 5 intensity on the Saffir–Simpson hurricane wind scale, within the Atlantic Ocean to the north of the equator. They are among the strongest tropical cyclones that can ...

list of Category 5 Pacific hurricanes Category 5 hurricanes are tropical cyclones that reach Category 5 intensity on the Saffir–Simpson hurricane scale. They are by definition the strongest hurricanes that can form on planet Earth. They are rare in the northeastern Pacif ...

list of cloud types The list of cloud types groups all genera as ''high'' (cirro-, cirrus), ''middle'' (alto-), ''multi-level'' (nimbo-, cumulo-, cumulus), and ''low'' (strato-, stratus). These groupings are determined by the altitude level or levels in the troposphe ...

list of coastal weather stations of the United Kingdom Reports from these coastal stations and automatic weather logging stations in the British Isles are included in the extended Shipping Forecasts on BBC Radio 4 at 0048 and 0520 local time each day. The stations are listed in the order they are re ...

list of countries by carbon dioxide emissions This is a list of sovereign states and territories by carbon dioxide emissions due to certain forms of human activity, based on thEDGAR databasecreated by European Commission and Netherlands Environmental Assessment Agency released in 2018 ...

* list of countries by carbon dioxide emissions per capita *

list of Earth observation satellites Earth observation satellites are earth-orbiting spacecraft with sensors used to collect imagery and measurements of the surface of the earth. These satellites are used to monitor short-term weather, long-term climate change, natural disasters ...

list of lighthouses and lightvessels This article contains links to lists of lighthouses around the world. According to ''Lighthouse Directory'', there are more than 18,600 lighthouses worldwide. Africa *''Note: Click on the country or place name of your choice in the table bel ...

list of meteorological phenomena This glossary of meteorology is a list of terms and concepts relevant to meteorology and atmospheric science, their sub-disciplines, and related fields. A ...

* list of most polluting power stations *

list of named tropical cyclones Tropical cyclones are named for historical reasons and so as to avoid confusion when communicating with the public, as more than one tropical cyclone can exist at a time. Names are drawn in order from predetermined lists. They are usually assign ...

* list of Northern Indian Ocean tropical cyclone seasons (see also :North Indian cyclone seasons) *

* list of notable tropical cyclones *

list of power outages This is a list of notable wide-scale power outages. To be included, the power outage must conform to of the following criteria: * The outage must not be planned by the service provider. * The outage must affect at least 1k people. * The outage m ...

list of scientific journals in earth and atmospheric sciences A ''list'' is any set of items in a row. List or lists may also refer to: People * List (surname) Organizations * List College, an undergraduate division of the Jewish Theological Seminary of America * SC Germania List, German rugby union ...

list of Solar Cycles Solar cycles are nearly periodic 11-year changes in the Sun's activity that are based on the number of sunspots present on the Sun's surface. The first solar cycle conventionally is said to start in 1755 when Rudolf Wolf began extensive reporting o ...

(list of sunspot cycles) *

list of tornado-related deaths at schools These are all known tornadoes resulting in student deaths at primary and secondary schools in the United States from 1865 to 2015. For the deadliest tornado incidents, only fires/explosions and bombings have killed more students. List * August ...

* list of weather instruments *

list of weather records This is a list of weather records, a list of the most extreme occurrences of weather phenomena for various categories. Many weather records are measured under specific conditions—such as surface temperature and wind speed—to keep consistency ...

Little Ice Age The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region. It was not a true ice age of global extent. The term was introduced into scientific literature by François E. Matthes in 1939. Ma ...

(LIA) * Local storm report *

(see same for "low-pressure cell") * (lowest elevations: see)

list of places on land with elevations below sea level This is a list of places on land below mean sea level. Places artificially created such as tunnels, mines, basements, and dug holes, or places under water, or existing temporarily as a result of ebbing of sea tide etc., are not included. Places ...

* (luminous pollution)

light pollution Light pollution is the presence of unwanted, inappropriate, or excessive use of artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting, during the day ...

(photopollution) *

lunar phase Concerning the lunar month of ~29.53 days as viewed from Earth, the lunar phase or Moon phase is the shape of the Moon's directly sunlit portion, which can be expressed quantitatively using areas or angles, or described qualitatively using the t ...

M

Madden–Julian oscillation The Madden–Julian oscillation (MJO) is the largest element of the intraseasonal (30- to 90-day) variability in the tropical atmosphere. It was discovered in 1971 by Roland Madden and Paul Julian of the American National Center for Atmospheric R ...

(MJO) *

magnetic storm A geomagnetic storm, also known as a magnetic storm, is a temporary disturbance of the Earth's magnetosphere caused by a solar wind shock wave and/or cloud of magnetic field that interacts with the Earth's magnetic field. The disturbance that d ...

(geomagnetic storm) *

magnetopause The magnetopause is the abrupt boundary between a magnetosphere and the surrounding plasma. For planetary science, the magnetopause is the boundary between the planet's magnetic field and the solar wind. The location of the magnetopause is d ...

magnetosheath The magnetosheath is the region of space between the magnetopause and the bow shock of a planet's magnetosphere. The regularly organized magnetic field generated by the planet becomes weak and irregular in the magnetosheath due to interaction with ...

magnetosphere In astronomy and planetary science, a magnetosphere is a region of space surrounding an astronomical object in which charged particles are affected by that object's magnetic field. It is created by a celestial body with an active interior dynam ...

marine west coast climate An oceanic climate, also known as a marine climate, is the humid temperate climate sub-type in Köppen classification ''Cfb'', typical of west coasts in higher middle latitudes of continents, generally featuring cool summers and mild winters ( ...

(maritime climate) (

oceanic climate An oceanic climate, also known as a marine climate, is the humid temperate climate sub-type in Köppen classification ''Cfb'', typical of west coasts in higher middle latitudes of continents, generally featuring cool summers and mild winters ( ...

) *

Mars Climate Orbiter The ''Mars Climate Orbiter'' (formerly the Mars Surveyor '98 Orbiter) was a robotic space probe launched by NASA on December 11, 1998, to study the Martian climate, Martian atmosphere, and surface changes and to act as the communications re ...

Mars Radiation Environment Experiment The Martian Radiation Experiment, or MARIE was designed to measure the radiation environment of Mars using an energetic particle spectrometer as part of the science mission of the 2001 Mars Odyssey spacecraft (launched on April 7, 2001). It was led ...

(Martian Radiation Experiment) (MARIE) *

maximum parcel level The maximum parcel level (MPL) is the highest level in the atmosphere that a moist convectively rising air parcel will reach after ascending from the level of free convection (LFC) through the free convective layer (FCL) and reaching the equilibri ...

(MPL) *

maximum sustained wind The maximum sustained wind associated with a tropical cyclone is a common indicator of the intensity of the storm. Within a mature tropical cyclone, it is found within the eyewall at a distance defined as the radius of maximum wind, or RMW. Unl ...

Max Planck Institute for Meteorology The Max Planck Institute for Meteorology (''Max-Planck-Institut für Meteorologie''; MPI-M) is an internationally renowned institute for climate research. Its mission is to understand Earth's changing climate. Founded in 1975, it is affiliated w ...

(MPI-M) *

mean radiant temperature __NOTOC__ The concept of mean radiant temperature (MRT) is used to quantify the exchange of radiant heat between a human and their surrounding environment, with a view to understanding the influence of surface temperatures on personal comfort. Mean ...

(MRT) *

Mediterranean climate A Mediterranean climate (also called a dry summer temperate climate ''Cs'') is a temperate climate sub-type, generally characterized by warm, dry summers and mild, fairly wet winters; these weather conditions are typically experienced in the ...

medium Earth orbit A medium Earth orbit (MEO) is an geocentric orbit, Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level.

(MEO) (intermediate circular orbit) (ICO) *

megathermal In climatology, the term ''megathermal'' (or less commonly, ''macrothermal'') is sometimes used as a synonym for ''tropical''. It comes from the two greek words "mega" and "thermal" meaning "big" and "heat". In order for a particular place to qualif ...

(macrothermal) *

melting Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which incre ...

mercury (element) Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver and was formerly named hydrargyrum ( ) from the Greek words, ''hydor'' (water) and ''argyros'' (silver). A heavy, silvery d-block A block ...

(see "Clean Air Act" under

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

) *

mercury-in-glass thermometer The mercury-in-glass or mercury thermometer was invented by physicist Daniel Gabriel Fahrenheit in Amsterdam (1714). It consists of a bulb containing mercury attached to a glass tube of narrow diameter; the volume of mercury in the tube is much le ...

mesopause The mesopause is the point of minimum temperature at the boundary between the mesosphere and the thermosphere atmospheric regions. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, the mesosphere is the cold ...

mesoscale convective complex A mesoscale convective complex (MCC) is a unique kind of mesoscale convective system which is defined by characteristics observed in infrared satellite imagery. They are long-lived, often form nocturnally, and commonly contain heavy rainfall, wi ...

(MCC) *

mesoscale convective system A mesoscale convective system (MCS) is a complex of thunderstorms that becomes organized on a scale larger than the individual thunderstorms but smaller than extratropical cyclones, and normally persists for several hours or more. A mesoscale con ...

(MCS) *

mesoscale convective vortex A mesovortex is a small-scale rotational feature found in a convective storm, such as a quasi-linear convective system (QLCS, i.e. squall line), a supercell, or the eyewall of a tropical cyclone. Mesovortices range in diameter from tens of miles to ...

(MCV) *

mesoscale meteorology Mesoscale meteorology is the study of weather systems smaller than synoptic scale systems but larger than Microscale meteorology, microscale and storm-scale cumulus systems. Horizontal dimensions generally range from around 5 kilometers to several ...

mesocyclone A mesocyclone is a meso-gamma mesoscale (or storm scale) region of rotation (vortex), typically around in diameter, most often noticed on radar within thunderstorms. In the northern hemisphere it is usually located in the right rear flank (back ...

* mesohigh *

mesolow A squall is a sudden, sharp increase in wind speed lasting minutes, as opposed to a wind gust, which lasts for only seconds. They are usually associated with active weather, such as rain showers, thunderstorms, or heavy snow. Squalls refer to the ...

mesonet In meteorology and climatology, a mesonet, portmanteau of mesoscale network, is a network of automated weather and, often, environmental monitoring stations designed to observe mesoscale meteorological phenomena and/or microclimates. Dry lines ...

mesosphere The mesosphere (; ) is the third layer of the atmosphere, directly above the stratosphere and directly below the thermosphere. In the mesosphere, temperature decreases as altitude increases. This characteristic is used to define its limits: it ...

mesothermal In climatology, the term mesothermal is used to refer to certain forms of climate found typically in the Earth's temperate zones. It has a moderate span of temperature, with winters not cold enough to sustain snow cover. Summers are warm within oc ...

(in climatology) *

mesovortex A mesovortex is a small-scale rotational feature found in a convective storm, such as a quasi-linear convective system (QLCS, i.e. squall line), a supercell, or the eyewall of a tropical cyclone. Mesovortices range in diameter from tens of miles to ...

Met Office The Meteorological Office, abbreviated as the Met Office, is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy and is led by CEO Penelope E ...

(previously Meteorological Office) (the UK's national weather service) * meteorological history of Hurricane Katrina *

Meteorological Service of Canada The Meteorological Service of Canada (MSC; french: Service météorologique du Canada – SMC) is a division of Environment and Climate Change Canada, which primarily provides public meteorological information and weather forecasts and warnings ...

(MSC) *

metrology Metrology is the scientific study of measurement. It establishes a common understanding of units, crucial in linking human activities. Modern metrology has its roots in the French Revolution's political motivation to standardise units in Fran ...

* Miami Tornado (of May 12, 1997) * Miami tornadoes of 2003 *

microclimate A microclimate (or micro-climate) is a local set of atmospheric conditions that differ from those in the surrounding areas, often with a slight difference but sometimes with a substantial one. The term may refer to areas as small as a few squ ...

microscale meteorology Microscale meteorology or micrometeorology is the study of short-lived atmospheric phenomena smaller than mesoscale, about or less. These two branches of meteorology are sometimes grouped together as "mesoscale and microscale meteorology" (MMM) ...

Mid-Atlantic United States flood of 2006 The Mid-Atlantic United States flood of 2006 was a significant flood that affected much of the Mid-Atlantic region of the eastern United States. The flooding was very widespread, affecting numerous rivers, lakes and communities from upstate New Y ...

middle latitudes The middle latitudes (also called the mid-latitudes, sometimes midlatitudes, or moderate latitudes) are a spatial region on Earth located between the Tropic of Cancer (latitudes 23°26'22") to the Arctic Circle (66°33'39"), and Tropic of Caprico ...

midnight Midnight is the transition time from one day to the next – the moment when the date changes, on the local official clock time for any particular jurisdiction. By clock time, midnight is the opposite of noon, differing from it by 12 hours. ...

* millimeter cloud radar (millimeter wave cloud radar) (MMCR) *

misoscale meteorology Misoscale is an unofficial scale of meteorological phenomena that ranges in size from to about . This scale was proposed by Ted Fujita, the founder of the Fujita scale, to classify phenomenon of the order of the rotation within a thunderstorm, the ...

mist Mist is a phenomenon caused by small droplets of water suspended in the cold air, usually by condensation. Physically, it is an example of a dispersion. It is most commonly seen where water vapor in warm, moist air meets sudden cooling, such a ...

mixed layer The oceanic or limnological mixed layer is a layer in which active turbulence has homogenized some range of depths. The surface mixed layer is a layer where this turbulence is generated by winds, surface heat fluxes, or processes such as evaporat ...

mixing ratio In chemistry and physics, the dimensionless mixing ratio is the abundance of one component of a mixture relative to that of all other components. The term can refer either to mole ratio (see concentration) or mass ratio (see stoichiometry). In at ...

moisture Moisture is the presence of a liquid, especially water, often in trace amounts. Small amounts of water may be found, for example, in the air (humidity), in foods, and in some commercial products. Moisture also refers to the amount of water vapo ...

molecular-scale temperature The molecular-scale temperature is the defining property of the U.S. Standard Atmosphere, 1962. It is defined by the relationship: : T_m(z)=\frac\cdot : ''Tm(z)'' is molecular-scale temperature at altitude ''z''; : ''M0'' is molecular weight of ...

moonlight Moonlight consists of mostly sunlight (with little earthlight) reflected from the parts of the Moon's surface where the Sun's light strikes. Illumination The intensity of moonlight varies greatly depending on the lunar phase, but even the ful ...

N

NASA Clean Air Study __NOTOC__ The NASA Clean Air Study was a project led by the National Aeronautics and Space Administration (NASA) in association with the Associated Landscape Contractors of America (ALCA) in 1989, to research ways to clean the air in sealed envir ...

NASA Earth Observatory NASA Earth Observatory is an online publishing outlet for NASA which was created in 1999. It is the principal source of satellite imagery and other scientific information pertaining to the climate and the Environment (biophysical), environment whi ...

NASA World Wind NASA WorldWind is an open-source (released under the NOSA license and the Apache 2.0 license) virtual globe. According to the website (https://worldwind.arc.nasa.gov/), "WorldWind is an open source virtual globe API. WorldWind allow ...

(virtual globe) *

National Ambient Air Quality Standards The U.S. National Ambient Air Quality Standards (NAAQS, pronounced ) are limits on atmospheric concentration of six pollutants that cause smog, acid rain, and other health hazards. Established by the United States Environmental Protection Agency ...

(NAAQS) (in the US) *

National Center for Atmospheric Research The US National Center for Atmospheric Research (NCAR ) is a US federally funded research and development center (FFRDC) managed by the nonprofit University Corporation for Atmospheric Research (UCAR) and funded by the National Science Foundatio ...

(NCAR) (in the US) *

National Centers for Environmental Prediction The United States National Centers for Environmental Prediction (NCEP) delivers national and global weather, water, climate and space weather guidance, forecasts, warnings and analyses to its Partners and External User Communities. These prod ...

(NCEP) (in the US) *

National Climatic Data Center The United States National Climatic Data Center (NCDC), previously known as the National Weather Records Center (NWRC), in Asheville, North Carolina, was the world's largest active archive of weather data. Starting as a tabulation unit in New Orl ...

(NCDC) (in the US) *

National Emissions Standards for Hazardous Air Pollutants The National Emission Standards for Hazardous Air Pollutants (NESHAP) are air pollution standards issued by the United States Environmental Protection Agency (EPA). The standards, authorized by the Clean Air Act, are for pollutants not covered by ...

(NESHAPS) (in the US) * (National Environmental Satellite, Data and Information Service: see)

National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...

(NOAA) (in the US) *

National Geomagnetism Program The National Geomagnetism Program is a program directed by the USGS that monitors the Earth's magnetic field Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into spac ...

(in the US) *

National Hurricane Center The National Hurricane Center (NHC) is the division of the United States' NOAA/National Weather Service responsible for tracking and predicting tropical weather systems between the Prime Meridian and the 140th meridian west poleward to the 3 ...

(NHC) (in the US) * National Map (in the US) *

(NOAA) (in the US) * (National Severe Storms Forecast Center SSFC renamed)

Storm Prediction Center The Storm Prediction Center (SPC) is a US government agency A government or state agency, sometimes an appointed commission, is a permanent or semi-permanent organization in the machinery of government that is responsible for the oversight a ...

(SPC) (in the US) *

National Severe Storms Laboratory The National Severe Storms Laboratory (NSSL) is a National Oceanic and Atmospheric Administration (NOAA) weather research laboratory under the Office of Oceanic and Atmospheric Research. It is one of seven NOAA Research Laboratories (RLs). NSSL s ...

(NSSL) (in the US) *

National Snow and Ice Data Center The National Snow and Ice Data Center (NSIDC) is a United States information and referral center in support of polar and cryospheric research. NSIDC archives and distributes digital and analog snow and ice data and also maintains information abo ...

(NSIDC) (in the US) *

National Solar Observatory The National Solar Observatory (NSO) is a United States public research institute to advance the knowledge of the physics of the Sun. NSO studies the Sun both as an astronomical object and as the dominant external influence on Earth. NSO is headq ...

(in the US) *

National Weather Association The National Weather Association (NWA), founded in 1975, is an American professional association with a mission to support and promote excellence in operational meteorology and related activities. Background The National Weather Association is, ...

(NWA) (in the US) *

National Weather Center The National Weather Center (NWC), on the campus of the University of Oklahoma, is a confederation of federal, state, and academic organizations that work together to better understand events that take place in Earth's atmosphere over a wide range ...

(NWC) (in the US) *

National Weather Service bulletin for New Orleans region The National Weather Service bulletin for the New Orleans region of 10:11 a.m., August 28, 2005, was a particularly dire warning issued by the local National Weather Service, Weather Forecast Office in Slidell, Louisiana, warning of the devas ...

(at 10:11 a.m., August 28, 2005) *

National Weather Service The National Weather Service (NWS) is an Government agency, agency of the Federal government of the United States, United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weathe ...

(NWS) *

nautical almanac A nautical almanac is a publication describing the positions of a selection of celestial bodies for the purpose of enabling navigators to use celestial navigation to determine the position of their ship while at sea. The Almanac specifies for ea ...

* nephology *

nephoscope A nephoscope is a 19th-century instrument for measuring the altitude, direction, and velocity of clouds, using transit-time measurement. This is different from a nephometer, which is an instrument used in measuring the amount of cloudiness. Des ...

night sky The night sky is the nighttime appearance of celestial objects like stars, planets, and the Moon, which are visible in a clear sky between sunset and sunrise, when the Sun is below the horizon. Natural light sources in a night sky include ...

nimbus cloud A nimbostratus cloud is a multi-level, amorphous, nearly uniform and often dark grey cloud that usually produces continuous rain, snow or sleet but no lightning or thunder.nitrogen cycle The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biologi ...

* (nitrogen pollution: see)

eutrophication Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...

(see under Atmospheric deposition) *

NOAA Weather Radio All Hazards NOAA Weather Radio NWR; also known as NOAA Weather Radio All Hazards is an automated 24-hour network of VHF FM weather radio stations in the United States (U.S.) that broadcast weather information directly from a nearby National Weather Serv ...

(NWR) (of the US) *

noctilucent cloud Noctilucent clouds, or night shining clouds, are tenuous cloud-like phenomena in the upper atmosphere of Earth. When viewed from space, they are called polar mesospheric clouds (PMCs), detectable as a diffuse scattering layer of water ice cryst ...

North Atlantic tropical cyclone An Atlantic hurricane, also known as tropical storm or simply hurricane, is a tropical cyclone that forms in the Atlantic Ocean, primarily between the months of June and November. A hurricane differs from a cyclone or typhoon only on the basis of ...

North Pole The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface. It is called the True North Pole to distinguish from the Mag ...

numerical weather prediction Numerical weather prediction (NWP) uses mathematical models of the atmosphere and oceans to predict the weather based on current weather conditions. Though first attempted in the 1920s, it was not until the advent of computer simulation in th ...

O

observational astronomy Observational astronomy is a division of astronomy that is concerned with recording data about the observable universe, in contrast with theoretical astronomy, which is mainly concerned with calculating the measurable implications of physical m ...

(see "light pollution" in places) *

observatory An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysical, oceanography and volcanology are examples of disciplines for which observatories have been constructed. His ...

(see also

list of observatories This is a list of astronomical observatories ordered by name, along with initial dates of operation (where an accurate date is available) and location. The list also includes a final year of operation for many observatories that are no longer in ...

) *

ocean heat content In oceanography and climatology, ocean heat content (OHC) is a term for the energy absorbed by the ocean, where it is stored for indefinite time periods as internal energy or enthalpy. The rise in OHC accounts for over 90% of Earth’s excess the ...

(OHC) *

Ocean Prediction Center The Ocean Prediction Center (OPC), established in 1995, is one of the National Centers for Environmental Prediction's (NCEP's) original six service centers. Until 2003, the name of the organization was the Marine Prediction Center.Ocean Predictio ...

(OHC) *

occultation An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks ...

Office of Oceanic and Atmospheric Research Oceanic and Atmospheric Research (OAR) is a division of the National Oceanic and Atmospheric Administration (NOAA). OAR is also referred to as NOAA Research. NOAA Research is the research and development arm of NOAA and is the driving force beh ...

(OAR) *

1999 Oklahoma tornado outbreak The 1999 Oklahoma tornado outbreak was a significant tornado outbreak that affected much of the Central and parts of the Eastern United States, with the highest record-breaking wind speeds of . During this week-long event, 154 tornadoes touched ...

orographic lift Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and cr ...

outflow boundary An outflow boundary, also known as a gust front, is a storm-scale or mesoscale boundary separating thunderstorm-cooled air (outflow) from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually a ...

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

oxygen cycle Oxygen cycle refers to the movement of oxygen through the atmosphere (air), biosphere (plants and animals) and the lithosphere (the Earth’s crust). The oxygen cycle demonstrates how free oxygen is made available in each of these regions, as wel ...

ozone Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lo ...

ozone depletion Ozone depletion consists of two related events observed since the late 1970s: a steady lowering of about four percent in the total amount of ozone in Earth's atmosphere, and a much larger springtime decrease in stratospheric ozone (the ozone l ...

ozone depletion potential The ozone depletion potential (ODP) of a chemical compound is the relative amount of degradation to the ozone layer it can cause, with trichlorofluoromethane (R-11 or CFC-11) being fixed at an ODP of 1.0. Chlorodifluoromethane (R-22), for exampl ...

(ODP) *

ozone layer The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. It contains a high concentration of ozone (O3) in relation to other parts of the atmosphere, although still small in rela ...

(ozonosphere layer) * ozone-oxygen cycle

P

Pacific decadal oscillation The Pacific decadal oscillation (PDO) is a robust, recurring pattern of ocean-atmosphere climate variability centered over the mid-latitude Pacific basin. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20°N. O ...

paleoclimatology Paleoclimatology (British spelling, palaeoclimatology) is the study of climates for which direct measurements were not taken. As instrumental records only span a tiny part of Earth's history, the reconstruction of ancient climate is important to ...

paleomagnetism Paleomagnetism (or palaeomagnetismsee ), is the study of magnetic fields recorded in rocks, sediment, or archeological materials. Geophysicists who specialize in paleomagnetism are called ''paleomagnetists.'' Certain magnetic minerals in rock ...

paleotempestology Paleotempestology is the study of past tropical cyclone activity by means of geological proxies as well as historical documentary records. The term was coined by American meteorologist Kerry Emanuel. The usual approach in paleotempestology is ...

parts-per notation In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...

* photovore *

(PBL) *

pluvial lake A pluvial lake is a body of water that accumulated in a basin because of a greater moisture availability resulting from changes in temperature and/or precipitation. These intervals of greater moisture availability are not always contemporaneous ...

* pneumonia front *

polar circle A polar circle is a geographic term for a conditional circular line (arc) referring either to the Arctic Circle or the Antarctic Circle. These are two of the keynote circles of latitude (parallels). On Earth, the Arctic Circle is currently ...

polar climate The polar climate regions are characterized by a lack of warm summers but with varying winters. Every month in a polar climate has an average temperature of less than . Regions with polar climate cover more than 20% of the Earth's area. Most of ...

polar easterlies In the study of Earth's atmosphere, polar easterlies are the dry, cold prevailing winds that blow around the high-pressure areas of the polar highs at the North and South Poles.Glossary of Meteorology (2009).They are called Easterlies because the ...

* polar high *

polar ice cap A polar ice cap or polar cap is a high-latitude region of a planet, dwarf planet, or natural satellite that is covered in ice. There are no requirements with respect to size or composition for a body of ice to be termed a polar ice cap, nor a ...

* (polar light: see)

aurora (astronomy) An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of br ...

polar low A polar low is a mesoscale, short-lived atmospheric low pressure area, low pressure system (depression) that is found over the ocean areas poleward of the main polar front in both the Northern and Southern Hemispheres, as well as the Sea of Japan ...

* (polar mesospheric cloud)

* polar mesospheric summer echoes (PMSE) *

polar night The polar night is a phenomenon where the nighttime lasts for more than 24 hours that occurs in the northernmost and southernmost regions of Earth. This occurs only inside the polar circles. The opposite phenomenon, the polar day, or midnig ...

polar region The polar regions, also called the frigid geographical zone, zones or polar zones, of Earth are the regions of the planet that surround its geographical poles (the North Pole, North and South Poles), lying within the polar circles. These high l ...

* (polar reversal)

magnetic polarity reversal A geomagnetic reversal is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged (not to be confused with geographic north and geographic south). The Earth's field has alternated ...

polar stratospheric cloud Polar stratospheric clouds (PSCs) are clouds in the winter polar stratosphere at altitudes of . They are best observed during civil twilight, when the Sun is between 1 and 6 degrees below the horizon, as well as in winter and in more northerly l ...

(PSC) (nacreous cloud) *

polar vortex A circumpolar vortex, or simply polar vortex, is a large region of cold, rotating air that encircles both of Earth's polar regions. Polar vortices also exist on other rotating, low-obliquity planetary bodies. The term polar vortex can be used to ...

Polarization (waves) Polarization (also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the ...

(see under Polarization effects in everyday life) * pole shift theory *

positive streamer Lightning is a naturally occurring electrostatic discharge during which two electric charge, electrically charged regions, both in the atmosphere or with one on the land, ground, temporarily neutralize themselves, causing the instantaneous ...

post-glacial rebound Post-glacial rebound (also called isostatic rebound or crustal rebound) is the rise of land masses after the removal of the huge weight of ice sheets during the last glacial period, which had caused isostatic depression. Post-glacial rebound a ...

potential evaporation Potential evaporation (PE) or potential evapotranspiration (PET) is defined as the amount of evaporation that would occur if a sufficient water source were available. If the actual evapotranspiration is considered the net result of atmospheric d ...

* potential temperature *

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...

pressure gradient In atmospheric science, the pressure gradient (typically of Earth's atmosphere, air but more generally of any fluid) is a physical quantity that describes in which direction and at what rate the pressure increases the most rapidly around a particu ...

pressure gradient force In fluid mechanics, the pressure-gradient force is the force that results when there is a difference in pressure across a surface. In general, a pressure is a force per unit area, across a surface. A difference in pressure across a surface t ...

(PGF) *

pyrocumulus A flammagenitus cloud, also known as a flammagenitus, pyrocumulus cloud, or fire cloud, is a dense cumuliform cloud associated with fire or volcanic eruptions. A flammagenitus is similar dynamically in some ways to a firestorm, and the two phen ...

Q

* Quantitative precipitation estimation *

Quantitative precipitation forecast The quantitative precipitation forecast (abbreviated QPF) is the expected amount of melted precipitation accumulated over a specified time period over a specified area. A QPF will be created when precipitation amounts reaching a minimum threshold ...

Quasi-geostrophic equations While geostrophic motion refers to the wind that would result from an exact balance between the Coriolis force and horizontal pressure-gradient forces, quasi-geostrophic (QG) motion refers to flows where the Coriolis force and pressure gradient fo ...

R

radiance In radiometry, radiance is the radiant flux emitted, reflected, transmitted or received by a given surface, per unit solid angle per unit projected area. Radiance is used to characterize diffuse emission and reflection of electromagnetic radiatio ...

radiant barrier A radiant barrier is a type of building material that reflects thermal radiation and reduces heat transfer. Because thermal energy is also transferred by conduction and convection, in addition radiation, radiant barriers are often supplemented wit ...

radiant energy Radiant may refer to: Computers, software, and video games * Radiant (software), a content management system * GtkRadiant, a level editor created by id Software for their games * Radiant AI, a technology developed by Bethesda Softworks for ''The ...

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

radiation hormesis Radiation hormesis is the hypothesis that low doses of ionizing radiation (within the region of and just above natural background levels) are beneficial, stimulating the activation of repair mechanisms that protect against disease, that are not ...

* radiation poisoning (radiation sickness) *

radiative cooling In the study of heat transfer, radiative cooling is the process by which a body loses heat by thermal radiation. As Planck's law describes, every physical body spontaneously and continuously emits electromagnetic radiation. Radiative cooling ha ...

radiological weapon Radiological warfare is any form of warfare involving deliberate radiation poisoning or contamination of an area with radiological sources. Radiological weapons are normally classified as weapons of mass destruction (WMDs), although radiologica ...

(radiological dispersion device DD *

radiosonde A radiosonde is a battery-powered telemetry instrument carried into the atmosphere usually by a weather balloon that measures various atmospheric parameters and transmits them by radio to a ground receiver. Modern radiosondes measure or calcula ...

radius of outermost closed isobar The radius of outermost closed isobar (ROCI) is one of the quantities used to determine the size of a tropical cyclone. It is determined by measuring the radii from the center of the storm to its outermost closed isobar in four quadrants, which ...

rain Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

rain fade Rain fade refers primarily to the absorption (optics), absorption of a microwave radio frequency (RF) signal by atmospheric rain, snow, or ice, and losses which are especially prevalent at frequencies above 11 GHz. It also refers to the degradation ...

(fading of signal by rain or snow) *

rain gauge A rain gauge (also known as udometer, pluvia metior, pluviometer, ombrometer, and hyetometer) is an instrument used by meteorologists and hydrologists to gather and measure the amount of liquid precipitation over a predefined area, over a period o ...

rain sensor A rain sensor or ''rain switch'' is a switching device activated by rainfall. There are two main applications for rain sensors. The first is a water conservation device connected to an automatic irrigation system that causes the system to shut do ...

rain shadow A rain shadow is an area of significantly reduced rainfall behind a mountainous region, on the side facing away from prevailing winds, known as its leeward side. Evaporated moisture from water bodies (such as oceans and large lakes) is carrie ...

rainbow A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured circular arc. Rainbows c ...

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...

rarefaction Rarefaction is the reduction of an item's density, the opposite of compression. Like compression, which can travel in waves (sound waves, for instance), rarefaction waves also exist in nature. A common rarefaction wave is the area of low relativ ...

RealClimate ''RealClimate'' is a commentary site (blog) on climatology. The site's contributors include climate scientists whose goal is to provide a response to developing stories and a context they feel is sometimes missing in mainstream commentary o ...

(commentary site on climate science) *

RealSky The Digitized Sky Survey (DSS) is a digitized version of several photographic astronomical surveys of the night sky, produced by the Space Telescope Science Institute between 1983 and 2006. Versions and source material The term Digitized Sky S ...

(digital photographic sky atlas) *

relative humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depe ...

relative pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and e ...

* (relief precipitation: see)

research balloon Research balloons are balloons that are used for scientific research. They are usually unmanned, filled with a lighter-than-air gas like helium, and fly at high altitudes. Meteorology, atmospheric research, astronomy, and military research may ...

resistance thermometer Resistance thermometers, also called resistance temperature detectors (RTDs), are sensors used to measure temperature. Many RTD elements consist of a length of fine wire wrapped around a heat-resistant ceramic or glass core but other constructio ...

(resistance temperature detector) (RTD) *

rime (frost) Rime ice forms when supercooled water liquid droplets freeze onto surfaces. Meteorologists distinguish between three basic types of ice forming on vertical and horizontal surfaces by deposition of supercooled water droplets. There are also interm ...

S

* Saffir-Simpson Hurricane Scale *

satellite temperature measurements Satellite temperature measurements are inferences of the temperature of the atmosphere at various altitudes as well as sea and land surface temperatures obtained from radiometric measurements by satellites. These measurements can be used to loc ...

* (Sea Islands Hurricane) 1893 Sea Islands Hurricane *

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...

* (sea level pressure)

sea surface temperature Sea surface temperature (SST), or ocean surface temperature, is the ocean temperature close to the surface. The exact meaning of ''surface'' varies according to the measurement method used, but it is between and below the sea surface. Air mass ...

(SST) *

severe weather Severe weather is any dangerous meteorological phenomenon with the potential to cause damage, serious social disruption, or loss of human life. Types of severe weather phenomena vary, depending on the latitude, altitude, topography, and atm ...

severe weather terminology (United States) This article describes severe weather terminology used by the National Weather Service (NWS) in the United States. The NWS, a government agency operating as an arm of the National Oceanic and Atmospheric Administration (NOAA) branch of the United ...

Skew-T log-P diagram A skew-T log-P diagram is one of four thermodynamic diagrams commonly used in weather analysis and forecasting. In 1947, N. Herlofson proposed a modification to the emagram that allows straight, horizontal isobars and provides for a large angle ...

sky The sky is an unobstructed view upward from the surface of the Earth. It includes the atmosphere and outer space. It may also be considered a place between the ground and outer space, thus distinct from outer space. In the field of astronomy, ...

skyglow Skyglow (or sky glow) is the diffuse luminance of the night sky, apart from discrete light sources such as the Moon and visible individual stars. It is a commonly noticed aspect of light pollution. While usually referring to luminance arising f ...

smoke Smoke is a suspension of airborne particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product ...

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

Solar and Heliospheric Observatory The Solar and Heliospheric Observatory (SOHO) is a European Space Agency (ESA) spacecraft built by a European industrial consortium led by Matra Marconi Space (now Airbus Defence and Space) that was launched on a Lockheed Martin Atlas IIAS l ...

solar azimuth angle The solar azimuth angle is the azimuth (horizontal angle with respect to north) of the Sun's position. This horizontal coordinate defines the Sun's relative direction along the local horizon, whereas the solar zenith angle (or its complementary ...

solar cell A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.

* solar collector *

solar constant The solar constant (''GSC'') is a flux density measuring mean solar electromagnetic radiation (total solar irradiance) per unit area. It is measured on a surface perpendicular to the rays, one astronomical unit (au) from the Sun (roughly the ...

solar cycle The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surfa ...

solar eclipse A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of the Earth, totally or partially. Such an alignment occurs during an eclipse season, approximately every six month ...

solar flare A solar flare is an intense localized eruption of electromagnetic radiation in the Sun's atmosphere. Flares occur in active regions and are often, but not always, accompanied by coronal mass ejections, solar particle events, and other solar phe ...

(see under

Hazards A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would allow them, even just theoretically, to cause damage to health, life, property, or any other interest of value. The probabi ...

) *

solar furnace A solar furnace is a structure that uses concentrated solar power to produce high temperatures, usually for industry. Parabolic mirrors or heliostats concentrate light (Insolation) onto a focal point. The temperature at the focal point may rea ...

* solar greenhouse (technical) *

solar heating A solar thermal collector collects heat by absorbing sunlight. The term "solar collector" commonly refers to a device for solar hot water heating, but may refer to large power generating installations such as solar parabolic troughs and sola ...

solar maximum Solar maximum is the regular period of greatest solar activity during the Sun's 11-year solar cycle. During solar maximum, large numbers of sunspots appear, and the solar irradiance output grows by about 0.07%. On average, the solar cycle takes ...

Solar Maximum Mission The Solar Maximum Mission satellite (or SolarMax) was designed to investigate Sun, Solar phenomena, particularly solar flares. It was launched on February 14, 1980. The SMM was the first satellite based on the Multimission Modular Spacecraft bus ...

solar minimum Solar minimum is the regular period of least solar activity in the Sun's 11-year solar cycle. During solar minimum, sunspot and solar flare activity diminishes, and often does not occur for days at a time. On average, the solar cycle takes abou ...

solar mirror A solar mirror contains a substrate with a reflective layer for reflecting the solar energy, and in most cases an interference layer. This may be a planar mirror or parabolic arrays of solar mirrors used to achieve a substantially concentrate ...

solar proton event In solar physics, a solar particle event (SPE), also known as a solar energetic particle (SEP) event or solar radiation storm, is a solar phenomenon which occurs when particles emitted by the Sun, mostly protons, become accelerated either in th ...

solar radiation Solar irradiance is the power per unit area (surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument. Solar irradiance is measured in watts per square metre (W/m ...

(solar irradiance) * (solar storm)

solar thermal collector A solar thermal collector collects heat by absorbing sunlight. The term "solar collector" commonly refers to a device for solar hot water heating, but may refer to large power generating installations such as solar parabolic troughs and sola ...

solar thermal energy Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in industry, and in the residential and commercial sectors. Solar thermal collectors are classified by the United St ...

solar updraft tower The solar updraft tower (SUT) is a design concept for a renewable-energy power plant for generating electricity from low temperature solar heat. Sunshine heats the air beneath a very wide greenhouse-like roofed collector structure surrounding t ...

solar variation The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surfac ...

solar wind The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the sola ...

solarium Solarium may refer to: * A sunroom, a room built largely of glass to afford exposure to the sun * A terrace (building) or flat housetop * The '' Solarium Augusti'', a monumental meridian line (or perhaps a sundial) erected in Rome by Emperor Augu ...

space geostrategy The politics of outer space includes space treaties, law in space, international cooperation and conflict in space exploration, international economics and the hypothetical political impact of any contact with extraterrestrial intelligence. Astr ...

(astrostrategy) (geostrategy in space) *

Space Science and Engineering Center The Space Science and Engineering Center (SSEC) is a research and development center with primary focus on Earth science research and technology to enhance understanding of the atmosphere of Earth, the other planets in the Solar System, and the co ...

(SSEC) *

space weather Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the time varying conditions within the Solar System, including the solar wind, emphasizing the space surrounding the Earth, including conditions in the ma ...

* (specific humidity: see)

(see under

Specific Humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depe ...

) *

squall A squall is a sudden, sharp increase in wind speed lasting minutes, as opposed to a wind gust, which lasts for only seconds. They are usually associated with active weather, such as rain showers, thunderstorms, or heavy snow. Squalls refer to the ...

squall line A squall line, or more accurately a quasi-linear convective system (QLCS), is a line of thunderstorms, often forming along or ahead of a cold front. In the early 20th century, the term was used as a synonym for cold front (which often are accompa ...

* (standard atmospheric pressure)

(standard atmosphere) *

standard conditions for temperature and pressure Standard temperature and pressure (STP) are standard sets of conditions for experimental measurements to be established to allow comparisons to be made between different sets of data. The most used standards are those of the International Union o ...

storm A storm is any disturbed state of the natural environment or the atmosphere An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmos ...

storm cellar A storm shelter or storm cellar is a type of underground bunker designed to protect the occupants from violent severe weather, particularly tornadoes. They are most frequently seen in the Midwest ("Tornado Alley") and Southeastern United States ( ...

storm chasing Storm chasing is broadly defined as the deliberate pursuit of any severe weather phenomenon, regardless of motive, but most commonly for curiosity, adventure, scientific investigation, or for news or media coverage. A person who chases storm ...

storm drain A storm drain, storm sewer (United Kingdom, United States, U.S. and Canada), surface water drain/sewer (United Kingdom), or stormwater drain (Australia and New Zealand) is infrastructure designed to Drainage, drain excess rain and ground water ...

(storm sewer) (stormwater drain) * storm-scale *

storm tide A storm surge, storm flood, tidal surge, or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low-pressure weather systems, such as cyclones. It is measured as the rise in water level above the no ...

storm track ''Storm Track'' was the first magazine for and about storm chasing. The magazine was in circulation between 1977 and 2002. History and profile ''Storm Track'' was started in 1977 by chasing pioneer David Hoadley following an informal meeting o ...

storm warning At sea, a storm warning is a warning issued by the National Weather Service of the United States when winds between 48 knots (89 km/h, 55 mph) and 63 knots (117 km/h, 73 mph) are occurring or predicted to occur soon. The wi ...

(see same for "storm watch") *

storm scale A storm is any disturbed state of the natural environment or the atmosphere of an astronomical body. It may be marked by significant disruptions to normal conditions such as strong wind, tornadoes, hail, thunder and lightning (a thunderstorm), ...

stormwater Stormwater, also spelled storm water, is water that originates from precipitation (storm), including heavy rain and meltwater from hail and snow. Stormwater can soak into the soil ( infiltrate) and become groundwater, be stored on depressed la ...

* stratopause * stratosphere * Stüve diagram * subarctic * subarctic climate * subtropical cyclone (see same for "subtropical depression" and for "subtropical storm") * subtropics (see same for "subtropical" and for "subtropical climate") * sudden ionospheric disturbance (SID) * sudden stratospheric warming * sun * sun dog (sundog) (parhelion) * sunlight * sunshower * sunspot (see under "Significant events") * supercell * surface temperature inversion *

* surface weather observation * synoptic scale meteorology

T

* teleconnection * temperature * temperature extremes * (temperature inversion) inversion (meteorology) * temperature record * temperature record of the past 1000 years * tephigram * The Weather Channel (TWC) * The Weather Network *

* thermodynamic temperature * thermometer * thunder * thundersnow *

(electrical storm) * TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) * Tornado warning, TOR * tornado * tornado climatology * tornado intensity * tornado warning * tornado watch * tornado emergency * tornadogenesis * torr (symbol: Torr) (millimetre of mercury) (mmHg) * Total Ozone Mapping Spectrometer (TOMS) * tropical climate * tropical cyclogenesis * tropical cyclone (tropical storm) (typhoon) (hurricane) * Tropical Cyclone Formation Alert (TCFA) * tropical cyclone observation * tropical cyclone prediction model * tropical cyclone rainfall climatology * tropical cyclone scales * Tropical Ocean-Global Atmosphere program (TOGA) * tropical rain belt * Tropical Rainfall Measuring Mission (TRMM) * Tropical Rainforest Heritage of Sumatra (in Indonesia) * (Tropical Research Institute) Smithsonian Tropical Research Institute (STRI) (in Panama) * Tropical upper tropospheric trough (TUTT) * tropical wave (African easterly wave) * tropopause * troposphere * Tropospheric Emission Spectrometer (TES) * tropospheric ozone * tsunami * Tsunami PTSD Center (Tsunami Post Traumatic Stress Disorder Center) * tsunami warning system * typical meteorological year

U

* U.S. state temperature extremes * ultraviolet * United States temperature extremes * urban heat island (UHI) * UV index

V

* vapor pressure * virtual temperature * vorticity

W

* waterspout * water vapor *

* weather forecasting * weather front * weather lore * Weather Modification Operations and Research Board (US) * Weather Prediction Center (WPC) * weather radar * weather satellite * wet-bulb potential temperature * wet-bulb temperature * wind * wind chill * wind direction * wind gradient * wind profiler * wind shear * wind speed * windcatcher * Windscale fire * winter storm * Winter Storm Warning * Winter Weather Advisory * World Asthma Day * World Climate Change Conference, Moscow * World Climate Conference * World Climate Programme * World Climate Report * World Climate Research Programme * World Meteorological Organization (WMO) * World Solar Challenge

Z

* Zonal wavenumber {{Index footer Meteorology, * Meteorology lists, Indexes of science articles, Meteorology topics ca:Fenomen meteorològic de:Portal:Wetter und Klima/Themenliste fr:Glossaire de la météorologie id:Fenomena meteorologi nl:Weer en klimaat van A tot Z nn:Vêrfenomen