- Industry: Weather
- Number of terms: 60695
- Number of blossaries: 0
- Company Profile:
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, ...
Thin silvery-blue cirrus-like clouds frequently seen during summer twilight conditions at high latitudes (above 50°) in both hemispheres. They are the highest visible clouds in the atmosphere, occurring in the upper mesosphere at heights of about 85 km, and are closely related to the polar mesospheric clouds seen in satellite observations at similar altitudes over the summer polar cap. Noctilucent clouds are now known to consist of tiny ice particles with dimensions of the order of tens of nanometers, growing in the extreme cold of the summer polar mesopause region. The condensation nuclei on which the particles grow are thought to be either smoke and dust particles of meteoric origin or large hydrated positive ions. Strong upwelling of air from below, associated with a pole-to-pole meridional circulation in the upper mesosphere, is responsible for both the extreme cold and the upward flux of water vapor. Although water-vapor mixing ratios are very low (less than 10 parts per million by volume) in the region, the temperatures are also low enough to produce a high degree of supersaturation at times. Anomalously strong radar echoes from the region, known as polar summer mesospheric echoes, are also associated with the clouds. Compare nacreous clouds, polar stratospheric clouds.
Industry:Weather
Un fluide dans lequel le tenseur des contraintes est proportionnel au taux de déformation, c'est-à-dire un fluide satisfaisant les équations de Navier – Stokes. Voir la force de viscosité.
Industry:Weather
L'abaissement de la température pendant la nuit, en raison d'une perte nette d'énergie rayonnante. Voir refroidissement par rayonnement.
Industry:Weather
1. un programme conjoint de l'u. s. les ministères du Commerce, la défense et transport durant les années 1980 et 1990 pour développer et déployer un réseau de radars météorologiques Doppler opérationnel. 2. le nom populaire pour le radar lui-même, le radar météorologique WSR - 88D, qui devint le radar du réseau opérationnel pour l'u. s. National Weather Service, u. s. Air Force et la Federal Aviation Administration durant le début et le milieu des années 1990. La longueur d'onde transmise nominal de la WSR - 88D est 10. 5 cm (bande S) et la largeur de faisceau circulaire nominal est 0. 95°.
Industry:Weather
Intervalle de temps entre le lever et le coucher du soleil.
Industry:Weather
A wind squall or succession of wind squalls, frequently accompanied by a spectacular low roll cloud or a series of such clouds, that occurs early in the morning, mainly in the late dry season (September–October) at places around the southern coast of the Gulf of Carpentaria region of northern Australia. The cloud lines may be up to a few kilometers across in the direction of travel, usually from the east or northeast, and are of considerable lateral extent, often stretching from horizon to horizon with a remarkably uniform cross section.
Industry:Weather
Ridges or deposits of rock debris transported by a glacier. Moraines are left after a glacier has receded, providing evidence of its former extent. Common forms are ground moraine, formed under a glacier; lateral moraine, along the sides; medial moraine, down the center; and end moraine, deposited at the terminus.
Industry:Weather
Plus basse température observée entre le coucher et le lever du soleil.
Industry:Weather
Происходит, когда сильный синоптического масштаба ветра дуют на вершине горы хребта, где ветры попали под сильной температурной инверсии, расположенный на высоте чуть выше вершины хребта. Результате падения ветров на стороне ли хребта оказались близко к поверхности и может разрушить здания и стянуть деревья. Смотреть '' и '' Чинук, foehn.
Industry:Weather
