The South-west region of the Caspian Sea has been repeatedly faced with hazardous dust phenomenon, during last decade. To determine the environmental impacts of the atmospheric systems on dust emission into the region, hourly averages variations of PM10 and PM2.5 and their relationship with some atmospheric parameters such as temperature, relative humidity and horizontal visibility were examined utilizing data from air pollution monitoring stations and airport synoptic-upper level station between May 2011 and December 2013. Spatial distribution or variation of Aerosol Optical Depth (AOD) along with visible images of Terra (or Aqua) has been used to monitor the dispersion of dust over Caspian Sea and its coastal area. The results showed that hourly average of ambient air pollutants; PMs condensations were reached to their maximum at 2:00 AM and follow a decreasing trend through the day. It may be concluded that the concentrations of ambient air pollutants, PMs variations happen in reverse direction with respect to temperature. Another conclusion may draw from different direction of changes between ambient air pollutants, PMs condensations and temperature was that they mainly come from local sources. These conditions also may be interpreted as an indication of the atmospheric boundary layer evolution and its turbulence role in the dispersion of ambient air pollutants, PM10 and PM2.5 to atmosphere. In dust free conditions, PMs condensations had increased by 37% and 17%, respectively. Study upon the relationship between horizontal visibility and relative humidity and particulate maters condensations was done by means of simple linear regression method.
South-west region of the Caspian Sea; Dust emission; Aerosol; Atmospheric parameter; PMs Condensations.