Anticyclone

As a high pressure area, also anticyclone or high called, refers to a mass of air at the bottom, which is horizontally characterized by a higher -than-ambient air pressure. He is conceptually compared to the low-pressure area.

Origin and Classification

In a (floor ) area of ​​high pressure air masses sink to large scale. The air is adiabatically heated, so that no condensation and hence no cloud formation can take place. Near the ground, the air flows out of the high pressure area towards low pressure areas, it diverges. There is therefore no formation of high fronts. During the descent of the air masses inversion forms. Here, the clouds will clear.

High pressure areas are divided into three categories according to the differences in their formation and development front:

A high level is an area of ​​high pressure that occurs at high altitudes and is thus presented in the amount weather maps. It is always associated with a surface low, since the heating surfaces of the vertical pressure gradient is lowered and the relative air pressure reduction is reflected on the ground with increasing altitude in a relatively higher to the horizontal atmospheric pressure. One can therefore derive an upper low in the reverse case of a high floor (even high thermal ).

A cold high occurs when the air, for example in winter over a cool land mass cools ( eg central Asian high ). The air then has a greater density and exerts a higher pressure on the base of. In the mid-latitudes, it can also occur in the form of flat wedges at the back of cyclones as a ridge of high pressure.

A dynamic high is generated by Rossby waves ( Polarfrontjetstream ). Great influence on the weather of Central Europe exerts this dynamic westerly flow ( Azores high ) from.

Currents in the high pressure area

The wind flow around a high pressure area is always anticyclonic (on the northern hemisphere, this is clockwise in the Southern Hemisphere counterclockwise). The direction of rotation is determined by the Coriolis force which deflects a moving air mass on the northern hemisphere in the direction of movement to the right and in the Southern Hemisphere according to the direction of movement to the left, the strength of this distraction from the equator to the poles increases and depends on the wind speed.

Naming Europe

The names used in Germany and some neighboring countries for low and high pressure areas that influence the weather in Europe are assigned by the Meteorological Institute of the Free University of Berlin.

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