Un anticyclone est une zone fermée de pressions atmosphériques élevées relativement à celles du voisinage [1].C'est le système inverse d'un cyclone, d'où son nom. Sur une carte synoptique de surface, l'anticyclone est caractérisé par des courbes isobares (généralement plus de 1013 hPa sur Terre) [1] avec une pression maximale au centre. Sur les cartes d'altitude, il est repérable ...

An anticyclone is a weather phenomenon defined as a large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere as viewed from above (opposite to a cyclone). Effects of surface-based anticyclones include clearing skies as well as cooler, drier air.

The Azores High also known as North Atlantic (Subtropical) High/Anticyclone or the Bermuda-Azores High, is a large subtropical semi-permanent centre of high atmospheric pressure typically found south of the Azores in the Atlantic Ocean, at the Horse latitudes.It forms one pole of the North Atlantic oscillation, the other being the Icelandic Low.The system influences the weather …

Un anticiclón es una zona atmosférica de alta presión, en la cual la presión atmosférica (corregida al nivel del mar) es superior a la del aire circundante. El aire de un anticiclón es más estable que el aire que lo circunda y desciende sobre el suelo desde las capas altas de la atmósfera, produciéndose un fenómeno denominado subsidencia.Los anticiclones, debido a lo anterior ...

The Great Smog of London, or Great Smog of 1952, was a severe air pollution event that affected London, England, in December 1952.A period of unusually cold weather, combined with an anticyclone and windless conditions, collected airborne pollutants—mostly arising from the use of coal—to form a thick layer of smog over the city. It lasted from Friday 5 December to …

Le moteur de la circulation atmosphérique sous les tropiques est le réchauffement solaire. À cause de l'inclinaison de 23,27 degrés de l'axe de rotation de la Terre, le Soleil n'est jamais à plus de quelques dizaines de degrés du zénith à midi tout au long de l'année dans les tropiques ce qui donne un maximum de réchauffement autour de l'équateur géographique.

Cumulonimbus (from Latin cumulus, "heaped" and nimbus, "rainstorm") is a dense, towering vertical cloud, typically forming from water vapor condensing in the lower troposphere that builds upward carried by powerful buoyant air currents. Above the lower portions of the cumulonimbus the water vapor becomes ice crystals, such as snow and graupel, the interaction of which can …

A dry thunderstorm is a thunderstorm that produces thunder and lightning, but where most of its precipitation evaporates before reaching the ground. Dry lightning refers to lightning strikes occurring in this situation. Both are so common in the American West that they are sometimes used interchangeably.. Dry thunderstorms occur essentially in dry conditions, and their …

The Great Dark Spot (also known as GDS-89, for Great Dark Spot, 1989) was one of a series of dark spots on Neptune similar in appearance to Jupiter's Great Red Spot.In 1989, GDS-89 was the first Great Dark Spot on Neptune to be observed by NASA's Voyager 2 space probe. Like Jupiter's spot, Great Dark Spots are anticyclonic storms.However, their interiors are relatively …

Une dépression est une zone fermée de basse pression atmosphérique relative à celle du voisinage au même niveau. Sur une carte synoptique de surface, cela donne un système d'isobares dont la pression est minimale au centre [1].Les dépressions peuvent se retrouver en altitude ou en surface, dans le premier cas elles sont notées par un minimum de géopotentiel, …