- 行业: Weather
- Number of terms: 60695
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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 ice nucleus of biological origin, particularly bacteria (e.g., pseudomonas syringae) from plant surfaces. These organisms have threshold temperatures as high as −2°C, being active at the highest temperature known for natural nuclei. They were first identified in leaf litter, collected worldwide. Commercial application lies in nucleation of water spray drops for artificial snow on ski slopes.
Industry:Weather
An instrument for measuring atmospheric pressure. Two types of barometers are commonly used in meteorology: the mercury barometer and the aneroid barometer.
Industry:Weather
An extratropical surface cyclone with a central pressure that falls on the average at least 1 mb h−1 for 24 hours. This predominantly maritime, cold season event is usually found approximately 750 km downstream from a mobile 500-mb trough, within or poleward of the maximum westerlies, and within or ahead of the planetary-scale troughs.
Industry:Weather
An electrometer of the electrostatic type in which the potential to be measured is applied to two metal-coated quartz fibers, and the deflection due to their mutual repulsion is observed through a low-power microscope. The bifilar electrometer is used for potential measurements in atmospheric electricity studies. Compare unifilar electrometer.
Industry:Weather
An enlarged photographic print of a bathythermograph slide superimposed on the appropriate bathythermograph grid annotated with particulars of location and date. The U. S. Navy Hydrographic Office maintains a master file of nearly one million bathythermograph prints from all the oceans.
Industry:Weather
An average measure of turbulence in the stable boundary layer (SBL), defined as the ratio of e-folding depth of cooling to the temperature decrease at the surface. Because the SBL has no well-defined depth, and because the amount of cooling and turbulence intensity varies continuously with height, the bulk scale provides an overall measure of turbulence. Typical magnitudes vary from 3 m K−1 for light turbulence to 15 m K−1 for strong turbulence.
Industry:Weather
An atmospheric state in which density depends upon both temperature and pressure and in which the geostrophic wind varies with height and is related to the horizontal temperature gradient via the thermal wind equation.
Industry:Weather
An atmospheric model that, in addition to the advection of the circulation field, includes thermal advection processes, an explicit representation of the thermodynamic energy equation, and at least two vertical data levels. The inclusion of thermal advection processes, and in particular differential thermal advection between vertical levels, is essential to predict the development of new weather systems. Baroclinic models are the standard models used for making numerical weather forecasts by operational forecast centers.
Industry:Weather
An approximation to the dynamical equations of motion whereby density is assumed to be constant except in the buoyancy term, −g′, of the vertical velocity equation, where g is the gravitational acceleration and ′ is the density deviation. The approximation is reasonable if the vertical extent of the dynamics being considered is much smaller than the density scale height.
Industry:Weather
