synoptic analysis of dust systems in yazd province

dust is a common atmospheric phenomenon in iran especially in central arid regions.  this severely affects environment as well as resident’s health. among the results of this phenomenon are respiratory diseases, bash radiation, accelerated soil erosion, desertification and degradation of ecosystems. some dusts are originated from local desert conditions but adjacency to neighboring countries deserts as saudi arabia has intensified this. yazd province due to its climate and geographical condition is always faced with dust in spring and summer times which leaves hazardous damages to the area. so, to understand the formation and origin of dust would help in reducing the damages. in this paper metrological station data was used. days coded 07 were extracted and eventually day 3 was used as a sample, synoptic maps of slp, 850 hpa, soil moisture and temperature maps, humidity, and wind direction and speed at different levels of the atmosphere, temperature and dust vorticity for the day before and the day after it was drawn. results have shown that due to the expansion of low pressure heated air tongue of lower latitudes, entered the iran from east and caused increased temperature. due to the low pressure gradient on the region in three days, the wind speed at ground level is very low. however, align the tongues on the 850 hpa due to the expansion of low-lying northern europe centers on the area; the speed amount of vertical motion and horizontal motions in the level is remarkable . atmospheric moisture maps indicate the general trend of decreasing moisture in the atmosphere in the three days. of soil moisture and temperature maps survey at 10 cm showed that the temperature in the first three days have risen sharply and soil moisture has started to decline in relation to it.