- 行业: Weather
- Number of terms: 60695
- Number of blossaries: 0
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The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. Founded in 1919, AMS has a membership of more than 14,000 professionals, ...
An evaluation of meteorological data received from a descending dropsonde. The dropsonde is a small expendable instrument package that is released from an aircraft. As it descends, it radio transmits pressure, temperature, and relative humidity data back to the aircraft. By tracking the position of the dropsonde using radio-navigation techniques (e.g., Global Positioning System (GPS)), wind speed and direction data can be obtained. The processed data are usually presented in terms of height, temperature, dewpoint, and winds at mandatory and significant pressure levels. A dropsonde observation is comparable to a rawinsonde observation. Data from the dropsonde are usually received and processed in the aircraft that dropped the instrument.
Industry:Weather
Any device that measures the size distribution of cloud droplets or raindrops, for example, certain optical particle probes.
Industry:Weather
A bottle, of one of various designs, that is released into the sea for use in studying currents. It contains a card, identifying the date and place of release, to be returned by the finder with the date and place of recovery. The bottle should be so designed and ballasted as to minimize direct wind effects. Since the path of a bottle can only be estimated between release point and recovery, and generally only a few percent are returned, this is an inefficient, although inexpensive, technique. Compare drift card.
Industry:Weather
A radiosonde with a parachute dropped from an airplane carrying receiving equipment for the purpose of obtaining an upper-air sounding during descent.
Industry:Weather
The frequency distribution of drop sizes (diameters, volumes) that is characteristic of a given cloud or of a given fall of rain. Most natural clouds have unimodal (single maximum) distributions, but occasionally bimodal distributions are observed. In convective clouds, the drop-size distribution is found to change with time and to vary systematically with height, the modal size increasing and the number decreasing with height. For many purposes a useful single parameter representing a given distribution is the volume median diameter, that is, that diameter for which the total volume of all drops having greater diameters is just equal to the total volume of all drops having smaller diameters. The drop- size distribution is one of the primary factors involved in determining the radar reflectivity of any fall of precipitation, or of a cloud mass.
Industry:Weather
A small spherical particle of any liquid; in meteorology, particularly a water droplet. There is no defined size limit separating droplets from drops of water, but it is sometimes convenient to denote two disparate size ranges, such as the oft-used distinction of liquid cloud particles (droplets) from liquid precipitation (drops), thereby implying that a maximum diameter of 0. 2 mm (0. 008 in. ) is the limit for droplets. See cloud droplet, drizzle drop, drop, raindrop.
Industry:Weather
The disruption of raindrops caused primarily by collisions with other raindrops. The distribution of drop fragments resulting from collisions is a complicated function of drop sizes, but generally the number of fragments increases with drop size. Thus, larger raindrops are more susceptible to breakup. Drop breakup is a limiting factor to the growth of raindrops by the collision–coalescence process.
Industry:Weather
Liquid particle, with shape maintained as a balance between surface tension and air drag when falling at terminal velocity under gravity in the atmosphere; drops less than 1 mm (0. 04 in. ) are approximately spherical. The shape may also be influenced by ambient electric field or thunderstorm strength.
Industry:Weather
A sea anchor or other parachute-shaped device for use in water. Drogues suspended at desired depths from buoys are used to determine the set and drift of currents at those depths, by tracking the motions that they give to the buoys at the surface.
Industry:Weather
A drop of water of diameter 0. 2–0. 5 mm (0. 008–0. 02 in. ) falling usually (but not always) from low stratus or stratocumulus cloud. Although this is the correct term for this size range, all water drops of diameter greater than 0. 2 mm are frequently termed raindrops, as opposed to cloud drops. Should such drops reach the ground, they can be felt on the upturned face.
Industry:Weather
