Korkeapainejärjestelmä

Korkeapainejärjestelmä, often referred to as an anticyclone, is a meteorological phenomenon characterized by a region of high atmospheric pressure relative to its surroundings. In the Northern Hemisphere, air within a high-pressure system generally circulates clockwise, while in the Southern Hemisphere, it circulates counterclockwise. This movement is a result of the Coriolis effect, which deflects winds due to the Earth's rotation.

High-pressure systems are typically associated with stable atmospheric conditions. As air sinks from higher altitudes towards the surface, it warms and dries, inhibiting cloud formation and precipitation. Consequently, areas under the influence of a korkeapainejärjestelmä often experience clear skies and fair weather, with reduced chances of rain or snow.

The formation of high-pressure systems can occur through various mechanisms. One common cause is the cooling of air over land in winter, making it denser and causing it to sink. Conversely, air can be forced downwards in the upper atmosphere, leading to high pressure at the surface. These systems can vary in size and duration, from small, localized anticyclones to vast, continental-scale high-pressure ridges that can persist for days or even weeks, significantly influencing weather patterns over large areas.