Review the Climatic Synoptic Types of North East of Iran and Their Relation with Circular Systems of the Representative Day Case Study: Mashhad City

In this study, among the daily data sets, 6 climatic variables including maximum mean of daily temperature, minimum of daily temperature, daily precipitation, vapor pressure, circle wind phenomenon and Meridian elements were used. Statistical period of data is from 21, March, 1981 up to 19, March 2003 for 23 years. Firstly, data base was formed in Matlab software as Pm*n matrix array. P matrix is a matrix data base in which rows (m) are time and columns (n) are climatic features. Then a cluster analysis has been performed for classification of data by integration method entering on standardized data matrix. Five distinctive types were determined for Mashad station (temperate type, rainy, glacial, very hot and dry windy and hot and dry). A representative day was specified for each type. At the end, circular patterns of atmospheric intermediate level (500 hpa) of each type were determined. With respect to circular pattern maps, the role of high elevation systems of Saudi Arabia and south of Iran in creation of hot and dry conditions and the role of Mediterranean drop down, dropdown of Iran’s north east and Siberian high pressure at the ground surface in creation of cold periods will be manifested.