شناسايي رفتار زماني - مكاني پرفشار سيبري در تراز دريا

Spatial-temporal behavior of Siberian high pressure in sea level

The present study the examines the spatial-temporal behavior of Siberian high using mean daily sea level pressure (SLP) in the Northern Hemisphere (20-80 lat and 40-140 Ion) from NCEP/NCAR reanalysis data for the period 1950-2005. The Original data were analyzed by means of Matlab and Surfer. The studies showed that Siberian high is the most important atmospheric center of action in Eurasia during the cool months. The Siberian high as a seasonal synoptic system for 8 October to 1 April dominated over Eurasia. Appearance of 1024 hpa isobar has been selected as the indicator of Siberian high occurrence. Spatial configuration of Siberian high in one hand depends on situation, extend and intensity of sub polar low pressure and on the other hands depends on Tabbat and Pamir Plateau. Therefore the shape of Siberian high is similar to an irregular triangle. Finally we recognize that the role of Siberian high in climate of Iran not only depends on intensity of this system but also depends on intensity of sub polar low pressure and leading tongue of Siberian high to Iran.