Analyzing the Synoptic Systems and Study the Change Trend in Dust (Case Study: Ardestan)

Dust storms and intensive winds are natural events which occur all around the world in arid and semi-arid areas. In the present study, changes in dust events during studied months, seasons and years (2000-2013) for Ardestan synoptic station and their relationship with drought (drought calculation using SPI index) were evaluated.. For this purpose statistics of selected station utilized in 14-years period (2000-2013). Codes extraction related to dust event (06 and 07) and data analysis conducted using MATLAB software and in order to study the changes trend in monthly and annual time series, non-parametric test statistics were calculated and then their significance was evaluated at 95 and 99 percent levels. Results showed that May and spring had highest dust events number compared to other months and seasons. Also, results showed that there was direct relationship between dust event and drought and years having intensive drought resulted to more duct events. Results indicated that in Mann-Kendall procedure, of total 13 data series, annual data series and in San-Estimator method, August had positive significant trend at 1% probability level and in Sen-Estimator method, data series in April and June months had increasing trend at 5% confidence level. Results of spatial analysis of anemometer data using WRplot showed that direction of dominant winds are toward south.