Statistical and synoptic analysis of erosive wind in North-West of Iran

The occurrence of erosive winds in the North West of Iran always causes damage to urban facilities and agricultural fields. By identifying behavior and synoptic patterns of Strong winds, necessary strategies can be chosen to deal with this destructive phenomenon. In this study, the fastest erosive winds and its steadiness coefficient were analyzed in selected stations of North West of Iran. Suitable model was introduced to predict these winds by using descriptive statistics analysis and logarithmic and order 6 polynomial trend. To understand the synoptic reasons for the occurrence of erosive winds in study area, 500hPa geopotential height, wind vector and sea level pressure maps were interpreted for the days with occurrence of erosive winds. Statistical analysis showed that the distribution of wind speed data follows from two-parameter Weibull and normal distributions. The results of the logarithmic and order 6 polynomial trend of data also indicate increase trend in erosive winds in Ardabil and Zanjan stations and decrease trend in wind steadiness coefficient at all stations. Synoptic analysis also showed that the erosive winds in stations under study were related to pressure gradient at sea level, the establishment of a relatively deep through and the polar front jet stream in 500hPa level.