Analysis of the Concurrence of Black Sea High Pressure System and Daily Precipitation in IRAN

In this research، for synchronization analysis of Black Sea high pressure with daily precipitation in IRAN data base have been created with using the sea level pressure data in Reanalysis II database in National Centers for Environmental Prediction (NCEP) /National Center for Atmospheric Research (NCAR). Temporal resolution of data is daily and spatial resolution is 2. 5 × 2. 5 degrees of arc. Framework covers the areas including of 20 -70 degrees east longitude and 20-70 degrees north latitude، consisting of 441 pixels. Second database is daily precipitation in 235 synoptic stations in IRAN. Study period is 45-year (1961 to 2004 AD) and includes 16071 days. In this matrix، rows are time and the columns are stations. The result shown that most relevant between precipitation in Iran and Black Sea high pressure is %66 in March and Lowest is %30 in August. Range of spatial in March is located in east، North East، North West and West South West of Iran. But in July، only the southern coast of Caspian Sea has precipitation associated with high pressure system in the Black Sea. Also Most of seasonal percent is %60 in winter season and Lowest is in summer with %38. Overall، more than 50 percent of the precipitation occurs at time of occur Black Sea high pressure system.