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Solar Reflectance
Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects all incident radiation). ''Surface albedo'' is defined as the ratio of Radiosity (radiometry), radiosity ''J''e to the irradiance ''E''e (flux per unit area) received by a surface. The proportion reflected is not only determined by properties of the surface itself, but also by the spectral and angular distribution of solar radiation reaching the Earth's surface. These factors vary with atmospheric composition, geographic location, and time (see position of the Sun). While directional-hemispherical reflectance factor is calculated for a single angle of incidence (i.e., for a given position of the Sun), albedo is the directional integration of reflectance over all solar angles in a given period. The temporal resolution may range from seconds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenland Albedo Change
Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenland are full Danish nationality law, citizens of Denmark and European Union citizenship, of the European Union. Greenland is one of the Special territories of members of the European Economic Area#Overseas countries and territories, Overseas Countries and Territories of the European Union and is part of the Council of Europe. It is the List of islands by area, world's largest island, and lies between the Arctic Ocean, Arctic and Atlantic oceans, east of the Arctic Archipelago, Canadian Arctic Archipelago. It is the location of the northernmost point of land in the world; Kaffeklubben Island off the northern coast is the world's Northernmost point of land, northernmost undisputed point of land—Cape Morris Jesup on the mainland was thought to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has a great affinity towards oxygen, passivation (chemistry), forming a protective layer of aluminium oxide, oxide on the surface when exposed to air. It visually resembles silver, both in its color and in its great ability to reflect light. It is soft, magnetism, nonmagnetic, and ductility, ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the abundance of the chemical elements, 12th-most abundant element in the universe. The radioactive decay, radioactivity of aluminium-26, 26Al leads to it being used in radiometric dating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global temperatures is Scientific consensus on climate change, driven by human activities, especially fossil fuel burning since the Industrial Revolution. Fossil fuel use, Deforestation and climate change, deforestation, and some Greenhouse gas emissions from agriculture, agricultural and Environmental impact of concrete, industrial practices release greenhouse gases. These gases greenhouse effect, absorb some of the heat that the Earth Thermal radiation, radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary gas driving global warming, Carbon dioxide in Earth's atmosphere, has increased in concentratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Planet
An ocean world, ocean planet or water world is a type of planet or natural satellite that contains a substantial amount of water in the form of oceans, as part of its hydrosphere, either beneath the planetary surface, surface, as subsurface oceans, or on the surface, potentially submerging all dry land. The term ''ocean world'' is also used sometimes for astronomical bodies with an ocean composed of a different fluid or thalassogen, such as lava (the case of Io (moon), Io), ammonia (in a eutectic mixture with water, as is likely the case of Titan (moon), Titan's inner ocean) or hydrocarbons (like on Titan's surface, which could be the most abundant kind of exosea). The study of extraterrestrial oceans is referred to as planetary oceanography. Earth is the only astronomical object known to presently have bodies of liquid water on its surface, although subsurface oceans are suspected to exist on Jupiter's moons Europa (moon), Europa and Ganymede (moon), Ganymede and Saturn's mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenhouse Effect
The greenhouse effect occurs when greenhouse gases in a planet's atmosphere insulate the planet from losing heat to space, raising its surface temperature. Surface heating can happen from an internal heat source (as in the case of Jupiter) or come from an external source, such as its host star. In the case of Earth, the Sun emits shortwave radiation (sunlight) that passes through greenhouse gases to heat the Earth's surface. In response, the Earth's surface emits outgoing longwave radiation, longwave radiation that is mostly Absorption (electromagnetic radiation), absorbed by greenhouse gases. The absorption of longwave radiation prevents it from reaching space, reducing the rate at which the Earth can cool off. Without the greenhouse effect, the Earth's average surface temperature would be as cold as . This is of course much less than the 20th century average of about . In addition to naturally present greenhouse gases, burning of fossil fuels has greenhouse gas emissions, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bidirectional Reflectance Distribution Function
The bidirectional reflectance distribution function (BRDF), symbol f_(\omega_,\, \omega_), is a function of four real variables that defines how light from a source is reflected off an Opacity (optics), opaque surface. It is employed in the optics of real-world light, in computer graphics algorithms, and in computer vision algorithms. The function takes an incoming light direction, \omega_, and outgoing direction, \omega_ (taken in a coordinate system where the Normal (geometry), surface normal \mathbf n lies along the ''z''-axis), and returns the ratio of reflected radiance exiting along \omega_ to the irradiance incident on the surface from direction \omega_. Each direction \omega is itself Spherical coordinate system, parameterized by azimuth angle \phi and zenith angle \theta, therefore the BRDF as a whole is a function of 4 variables. The BRDF has units sr−1, with steradians (sr) being a unit of solid angle. Definition The BRDF was first defined by Fred Nicodemus around 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Directional-hemispherical Reflectance
Directional-hemispherical reflectance is the reflectance of a surface under direct illumination (with no diffuse component). Directional-hemispherical reflectance is the integral of the bidirectional reflectance distribution function over all viewing directions. It is sometimes called "black-sky albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...". References See also * Bi-hemispherical reflectance Electromagnetic radiation Climatology {{Optics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joint Polar Satellite System
The Joint Polar Satellite System (JPSS) is the latest generation of U.S. polar-orbiting, non-geosynchronous, environmental satellites. JPSS will provide the global environmental data used in numerical weather prediction models for forecasts, and scientific data used for climate monitoring. JPSS will aid in fulfilling the mission of the U.S. National Oceanic and Atmospheric Administration (NOAA), an agency of the Department of Commerce. Data and imagery obtained from the JPSS will increase timeliness and accuracy of public warnings and forecasts of climate and weather events, thus reducing the potential loss of human life and property and advancing the national economy. The JPSS is developed by the National Aeronautics and Space Administration (NASA) for the National Oceanic and Atmospheric Administration (NOAA), who is responsible for operation of JPSS. Three to five satellites are planned for the JPSS constellation of satellites. JPSS satellites will be flown, and the scientific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suomi NPP
The Suomi National Polar-orbiting Partnership (Suomi NPP), previously known as the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) and NPP-Bridge, is a weather satellite operated by the United States National Oceanic and Atmospheric Administration (NOAA). It was launched in 2011 and is currently in operation. Suomi NPP was originally intended as a pathfinder for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) program, which was to have replaced NOAA's Polar Operational Environmental Satellites (POES) and the U.S. Air Force's Defense Meteorological Satellite Program (DMSP). Suomi NPP was launched in 2011 after the cancellation of NPOESS to serve as a stop-gap between the POES satellites and the Joint Polar Satellite System (JPSS) which will replace them. Its instruments provide climate measurements that continue prior observations by NASA's Earth Observing System (EOS). Name The satellite is name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aqua (satellite)
Aqua (EOS PM-1) is a NASA scientific research satellite in orbit around the Earth, studying the Precipitation (meteorology), precipitation, evaporation, and Water cycle, cycling of water. It is the second major component of the Earth Observing System (EOS) preceded by Terra (satellite), Terra (launched 1999) and followed by Aura (satellite), Aura (launched 2004). The name "Aqua" comes from the Latin word for water. The satellite was launched from Vandenberg Air Force Base on May 4, 2002, aboard a Delta II Launch vehicle, rocket. Aqua operated in a Sun-synchronous orbit as the third in the satellite formation called the "A-train (satellite constellation), A Train" with several other satellites (OCO-2, the Japanese GCOM, GCOM W1, PARASOL, CALIPSO, CloudSat, and Aura (satellite), Aura) for most of its first 20 years; but in January 2022 Aqua left the A-Train (as Cloud Sat, CALIPSO and PARASOL had already done) when, due to its fuel limitations, it transitioned to a free-drift mode, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terra (satellite)
Terra (EOS AM-1) is a multi-national scientific research satellite operated by NASA in a Sun-synchronous orbit around the Earth. It takes simultaneous measurements of Earth's atmosphere, land, and water to understand how Earth is changing and to identify the consequences for life on Earth. It is the flagship of the Earth Observing System (EOS) and the first satellite of the system which was followed by Aqua (launched in 2002) and Aura (launched in 2004). Terra was launched in 1999. The name "Terra" comes from the Latin word for Earth. A naming contest was held by NASA among U.S. high school students. The winning essay was submitted by Sasha Jones of Brentwood, Missouri. The identifier "AM-1" refers to its orbit, passing over the equator in the morning. Launch The satellite was launched from Vandenberg Air Force Base on December 18th, 1999, aboard an Atlas IIAS vehicle and began collecting data on February 24th, 2000. It was placed into a near-polar, sun-synchrono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MODIS
The Moderate Resolution Imaging Spectroradiometer (MODIS) is a satellite-based sensor used for earth and climate measurements. There are two MODIS sensors in Earth orbit: one on board the Terra (EOS AM) satellite, launched by NASA in 1999; and one on board the Aqua (EOS PM) satellite, launched in 2002. Since 2011, MODIS operations have been supplemented by VIIRS sensors, such as the one aboard Suomi NPP. The systems often conduct similar operations due to their similar designs and orbits (with VIIRS data systems deisgned to be compatible with MODIS), though they have subtle differences contributing to similar but not identical uses. The MODIS instruments were built by Santa Barbara Remote Sensing. They capture data in 36 spectral bands ranging in wavelength from 0.4 μm to 14.4 μm and at varying spatial resolutions (2 bands at 250 m, 5 bands at 500 m and 29 bands at 1 km). Together the instruments image the entire Earth every 1 to 2 days. They are designed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
