Recognition of Weather Types in Ardabil Synoptic Station and its Relationship With Atmospheric Circulation Patterns

Determination of weather types as one of the goals of Synoptic climatology is identification of similar weathers variables. Hence, weather types in fact visualize air masses. In other words, a weather type is a different set of atmospheric characteristics which is different from other series. Today, identification of weather type based on climatic variables is one of the important tools for climatologists to understand about the weather and climactic problems & disasters due to atmospheric circulations. On the other hand, the weather types are associated with surface events and by identification of these, environmental phenomena such as floods, pollution, pests, etc, are predictable. Many of the processes concerned with environmental problems, are affected by atmospheric circulations. Since in synoptic studies, the relationship between changes in atmospheric circulation patterns and environmental phenomena and processes are reviewed, the results of these studies could lead to explain and predict phenomena and environmental conditions.Research Methodology In this paper, in order to determine and investigate the synoptic weather types in Ardabil synoptic station, 18 climatic variables such as wet and dry bulb temperature, relative humidity, direction & speed of wind (for 03, 09 & 15 GMT) mean of rainfall, maximum and minimum of temperature belong to Ardebil synoptic station in years 1978 – 2005 have been used. 9918 days has had complete data of the above variables. First, a P Matrix (9918×18) created and then the data standardize process has been performed. On this Matrix, by using cluster analysis, weather types of this station have recognized. based on correlations, 6 days selected as representative days of 6 synoptic types in Ardabil synoptic station. So, in these representative days, climatic characteristics of sea level pressure and 500 hecto-pascal geopotential height maps were investigated