تاوه قطبي و اثرات آن بر اقليم

Polar Vortex and its Effects on Climate

The arctic is one of the most sensitive regions on the earth to the global climate change due to both natural variability and the anthrepogenic climate forcing_ On the other hand, the air circulation in this region is in a more delicate balance among its subsystems of the general atmospheric circulation because every change in the centers of action atmospheric as follows: subtropical high pressure centers, inlcrtropical convergence zone and etc occurs, it will have influence on intensity and breakdown of polar vortex. Close association between location and size variation in the polar vortex and surface and middleiropospheric thermal and pressure characteristics. The change in vortex area appears mainly to reflect a change in mean tropospheric temperature, but with some modification caused by a change in mean surface pressure in temperate latitudes (Angell and Korshover. 1992). Therefore, identification of vortex characteristic and makes size area vortex measurement a valuable tool in monitoring and understanding climate change. Furthermore, considered is the displacement locations centers vortex and its change area lead to from a temporal trend characteristics, identification this trends can he used to produce the forecasts long live.