عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Dust storms are common weather phenomena in arid and semi-arid regions. In this research, the conditions affecting the occurrence of dust storms in the northwest of Iran in October 2013 have been investigated using the combined visual and remote sensing method. For this purpose, after checking the horizontal visibility and wind direction and speed in the ground observation stations, the data of the research of different levels of the atmosphere were obtained from the NOA site according to the research topic. These data have been used to check the visibility conditions and draw the required maps in the Grads software environment. Next, using MODIS (Equa) satellite images and atmospheric infrared sensor, the phenomenon of dust in the study area was revealed and finally, the images used were prepared by overlaying the real color images of the ground surface reflection and the amount of dust. The results showed that in the conditions where there is a high pressure gradient between the high pressure and low pressure center in the northwestern region of the country, accompanied by the westerly wind wave in the middle levels of the atmosphere and the activity of the upper level wind, the air flow from the countries of Iraq and Syria at a high speed to It blew from the north-west side of Iran and caused the dust storm in the north-west of Iran in October 2012. Remote sensing images confirm the direction of dust movement according to the air flow in the area.