The effect of wind direction on dust transfer toward the Persian Gulf

Introduction: Dust is a natural process in desert areas, which is caused by the effect of strong winds on the surface of the soil. The aim of this study is to investigate the conditions of the formation and expanding the dust storm formed in Iraq to the Khuzestan province in February, 2017.   Materials and methods: The synoptic analysis was conducted using meteo-rological parameters from ERA-interim and observation data from the Ahwaz station. In addition, the EUMETSAT image, the DREAM and the HYSPLIT model output were used.   Results: As the results show, regarding to the storm, dust in low- pressure area located over Iran is expanded toward the west associated with the tough 500 hPa . With the formation of the high-pressure area in Syria, a pressure gradient is formed in Iraq resulting the northwest wind with the wind speed of 28 knots s (14 m/s) in 925 hPa. These conditions have led to transport the dust from Iraq toward southwest of Iran. A jet stream is formed 12 h before entering the dust from Iraq to Iran, at 900 hPa. The HYSPLIT model predicts the particle’s motion along the northwest winds, and is matched with the wind field in synoptic structure.   Conclusion: According to this study, the most important factors in dust trans-port to the Persian Gulf are geographic location of the low- and high-pressure area and the formed northwest winds in Iraq.