Studying and Determining of Synoptic Patterns of Climatic Seasons in the West of Iran

Classifying the seasons is mainly carried out based on the daily movement of the sun. Around the world and especially within the middle latitudes as in Iran, there is not a full coordination between the seasons of a year and planetary seasons. Accordingly, in addition to planetary definitions,numerous definitions have been offered for seasons based on meteorology and climatology criteria. Therefore,season is part of a year which is distinct from other parts, because of a regular frequency of the planetary or climatologic phenomena. In other word, natural season is a time period of calendar year distinguished by homogenous and congruent weather. The natural seasons i.e. spring, summer, fall and winter are calendar time intervals which are naturally determined through different types of the congruent climatic regimes like temperature and wind speed changes. In fact, in such a classifying the seasons are defined based upon climatic elements e.g. temperature and wind representing the climatic facts of that place, with or without connection to the calendar seasons. Based on the above statement, this paper aims to find out a real definition for each season in the west of Iran, in which the seasons will be defined based on the climatic facts of the region, not on the basis of a planetary definition.