Anticyclone

An anticyclone just below Southern Australia near Tasmania.
Hadley cell circulation tends to create anticyclonic patterns in the Horse latitudes, depositing drier air and contributing to the world's great deserts.

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).[1] Effects of surface-based anticyclones include clearing skies as well as cooler, drier air. Fog can also form overnight within a region of higher pressure.

Mid-tropospheric systems, such as the subtropical ridge, deflect tropical cyclones around their periphery and cause a temperature inversion inhibiting free convection near their center, building up surface-based haze under their base. Anticyclones aloft can form within warm-core lows such as tropical cyclones, due to descending cool air from the backside of upper troughs such as polar highs, or from large-scale sinking such as a subtropical ridge. The evolution of an anticyclone depends upon variables such as its size, intensity, and extent of moist convection, as well as the Coriolis force.[2]

  1. ^ "Glossary: Anticyclone". National Weather Service. Archived from the original on June 29, 2011. Retrieved January 19, 2010.
  2. ^ Rostami, Masoud; Zeitlin, Vladimir (2017). "Influence of condensation and latent heat release upon barotropic and baroclinic instabilities of vortices in a rotating shallow water f-plane model" (PDF). Geophysical & Astrophysical Fluid Dynamics. 111 (1): 1–31. Bibcode:2017GApFD.111....1R. doi:10.1080/03091929.2016.1269897. S2CID 55112620.