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Raindrop Size Distribution
The raindrop size distribution (''DSD''), or granulometry of rain, is the distribution of the number of raindrops according to their diameter (D). Three processes account for the formation of drops: water vapor condensation, accumulation of small drops on large drops and collisions between sizes. According to the time spent in the cloud, the vertical movement in it and the ambient temperature, drops have a very varied history and a distribution of diameters from a few micrometers to a few millimeters. Definition In general, the drop size distribution is represented as a truncated gamma function for diameter zero to the maximum possible size of rain droplets. The number of drop with diameter D is therefore : N(D) = N_0 D^\mu e^ with N_0, \mu and \Lambda as constants. Marshall-Palmer distribution The most well-known study about raindrop size distribution is from Marshall and Palmer done at McGill University in Montréal in 1948. They used stratiform rain with \mu = 0 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DSD Marshall-Palmer
DSD may refer to: Medical * Detrusor sphincter dyssynergia, disorder of urination * Disorders of sex development, differences of sex differentiation Technology * Data structure diagram of a data model * Direct Stream Digital, Sony and Philips digital recording trademark * Document Structure Description, a schema language for describing valid XML Organizations * Defence Signals Directorate, an Australian intelligence agency * Department for Social Development * Det Stavangerske Dampskibsselskap, a Norwegian transport and shipping company * Drainage Services Department, Hong Kong * Davis School District, Utah * Delaware School for the Deaf Government * United States District Court for the District of South Dakota, abbreviation in case decisions * Downing Street Declaration, by UK PM and Irish Taoiseach * New Zealand Distinguished Service Decoration, a medal awarded by the New Zealand Defence Force Media * '' Do Something Different'', a British CBBC television show Other uses * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disdrometer
A disdrometer is an instrument used to measure the Raindrop size distribution, 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 Air traffic control, traffic control, scientific examination, airport observation systems, and hydrology. The latest disdrometers employ microwave or laser technologies. 2D video disdrometers can be used to analyze individual raindrops and snowflakes. See also * Rain gauge * Snow gauge References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Water Content
The liquid water content (LWC) is the measure of the mass of the water in a cloud in a specified amount of dry air. It is typically measured per volume of air (g/m3) or mass of air (g/kg) (Bohren, 1998). This variable is important in figuring out which types of clouds are likely to form and is strongly linked to three other cloud microphysical variables: the cloud drop effective radius, the cloud drop number concentration, and the cloud drop size distribution (Wallace, 2006). Being able to determine the cloud formations that are likely to occur is extremely useful for weather forecasting as cumulonimbus clouds are related to thunderstorms and heavy rain whereas cirrus clouds are not directly associated with precipitation. Characteristics The liquid water content of a cloud varies significantly depending on the type of clouds present in the atmosphere at a given location. The classification of the cloud is highly related to the liquid water content as well as the origin of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloud Drop Effective Radius
The cloud drop effective radius (alternatively cloud effective radius or simply effective radius when in context) is a weighted mean of the size distribution of cloud droplets. The term was defined in 1974 by James E. Hansen and Larry Travis as the ratio of the third to the second moment of a droplet size distribution to aid in the inversion of remotely sensed data. Physically, it is an area weighted radius of the cloud drop particles. Mathematically, this can be expressed as r_e = \dfrac. The global effective particle radius has different values for water and ice clouds: the former is around 14 μm, whereas for ice it is around 25 μm. Studies also indicate that the effective cloud droplet radius is larger over oceans than over ground by 15%–20%. By contrast, the difference in the ice particle size over land and oceans is much smaller (only 5%). See also *Liquid water content *Raindrop size distribution The raindrop size distribution (''DSD''), or granulometry of rain, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Oceanic And Atmospheric Administration
The National Oceanic and Atmospheric Administration (NOAA ) is an American scientific and regulatory agency charged with Weather forecasting, forecasting weather, monitoring oceanic and atmospheric conditions, Hydrography, charting the seas, conducting deep-sea exploration, and managing fishing and protection of marine mammals and endangered species in the US exclusive economic zone. The agency is part of the United States Department of Commerce and is headquartered in Silver Spring, Maryland. History NOAA traces its history back to multiple agencies, some of which are among the earliest in the federal government: * United States Coast and Geodetic Survey, formed in 1807 * National Weather Service, Weather Bureau of the United States, formed in 1870 * United States Fish Commission, Bureau of Commercial Fisheries, formed in 1871 (research fleet only) * NOAA Commissioned Corps, Coast and Geodetic Survey Corps, formed in 1917 The most direct predecessor of NOAA was the Enviro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nimbostratus Cloud
A nimbostratus cloud is a multilevel, amorphous, nearly uniform, and often dark-grey cloud that usually produces continuous rain, snow, or sleet, but no lightning or thunder. in the Oxford Dictionaries Online. Although it is usually a low-based stratiform cloud, it actually forms most commonly in the middle level of the troposphere and then spreads vertically into the low and high levels. Nimbostratus usually produces precipitation over a wide area. The prefix '' nimbo-'' comes from the Latin word ', which means "rain bearing cloud" Downward-growing nimbostratus can have the same vertical extent as most large upward-growing [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Convection
Atmospheric convection is the vertical transport of heat and moisture in the atmosphere. It occurs when warmer, less dense air rises, while cooler, denser air sinks. This process is driven by parcel-environment instability, meaning that a "parcel" of air is warmer and less dense than the surrounding environment at the same altitude. This difference in temperature and density (and sometimes humidity) causes the parcel to rise, a process known as buoyancy. This rising air, along with the compensating sinking air, leads to mixing, which in turn expands the height of the planetary boundary layer (PBL), the lowest part of the atmosphere directly influenced by the Earth's surface. This expansion contributes to increased winds, cumulus cloud development, and decreased surface dew points (the temperature below which condensation occurs). Convection plays a crucial role in weather patterns, influencing cloud formation, wind, and the development of thunderstorms, which can be associa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Météo-France
Météo-France is the official French meteorological administration, also offering services to Andorra and Monaco. It has the powers of the state and can exercise them in relation to meteorology. Météo-France is in charge of observing, studying, and forecasting weather and monitoring snowpack. The organization also issues weather warnings for the Metropole and the overseas territories. Météo-France is also in charge of recording and predicting the climate. Organisation The organisation was established by decree in June 1993 and is a department of the Ministry of Transportation. It is headquartered in Paris but many domestic operations have been decentralised to Toulouse. Its budget of around €300 million is funded by state grants, aeronautic royalties and sale of commercial services. Météo-France has a particularly strong international presence, and is the French representative at the World Meteorological Organization. The organisation is a leading member of EUM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
