The role of Siberian high in distribution of the daily minimum temperatures in Iran

Extended abstract1- Introduction Siberian high is a large synoptic system in planet scale that considers the most important center of atmosphere action for cold period in Eurasia. This high that depend on the coldest and the most condensed air mass in north hemisphere, concentrate itself as a seasonal and semi – permanent synaptic system between Baykal and Balkhash lakes , and it’s western tongue affect the climate of extensive regions of Iran. Therefore, the goal of this synoptic study is to explain key interactions between the atmosphere and surface environment and in other words exploration of the relationship between the circulation patterns of Siberian high pressure and minimum temperatures in Iran. Up to now, many studies about Siberian high have been done by several individuals that we will refer to some studies which have been done in Iran and world. In the world, Lydolph(1977), Ding and Krishnamurti(1987), Sahsamanoglou et al (1991) , Zhang et al (1996) , Mokhov and Petukhov (1999), Choen et al (2001), Haghton et al(2001), Gong et al(2001,2002), Takaya and Nakamura (2004), Panagiotopoulos et al (2005) and Lingis and Thompson(2005) are individuals that have carried out investigations about siberian high. In Iran, the investigations have been done too which can point to investigations of Abdolhoseini (1358), Alijani (1369), Balighi (1375), Chokhachizadeh (1376), Jahanbakhsh et al (1378), Azizi and Yousefi (1384) and kaviani et al (2007). This research try to reveal the climatic impacts of pressure systems on Iran climate by using the statistic and synoptic methods study the role of Siberian high system at the Slp in spatial distribution of the minimum temperatures in Iran.2- MethodologyIn this research, for analyzing the temporal variations of the Siberian system have been applied the daily data of sea level pressure at 12GMT in NCEP NCAR database with spatial resolution of 2.5×2.5 in a 55 years period including 20089 days from Dey, 11th, 1329 to Dey, 10th,1384). To recognize and analyze the temporal patterns of Siberian high system and by considering the mean position of this system and it’s spatial developing relative to Iran and the maximum of it’s action intensity in sea level that often is conformity with surrounding and middle limits of Balkhash and Baykal lakes (Lingis and Thompson,2005, Gong et al 2002, Sahsamanoglou et al ,1991, kaviani et al, 1386 and Chokhachizadeh ,1376) we have selected the suitable framework of 62.5 – 120o east and 40 – 62.5o north for this system. Then, calculation and standardization of mean daily of sea level pres