Investigation and model simulation of dry and moist (haboob) convective dust storms in Yazd Province, central Iranian plateau.

In this study, two cases of regional dust storms occurred on 16/17 April 2018 and 27/28 April 2020 in Yazd Province, central Iranian plateau, were analyzed and simulated using the WRF-Chem model. The first case was a haboob type and the second one was a dust storm due to dry convection. In order to comprehensively investigate these types of dust storms, synoptic meteorological data at stations in Yazd Province, satellite observations, reanalysis data, and WRF-Chem model simulations have been synergized. During the dust storms, there was a dramatic decrease in visibility, with considerable changes in the ambient temperature and dew point profiles coincided with the arrival of the haboob. Although the decrease in visibility in Yazd City was less during the dry convection dust storm, the increase in temperature and decrease in surface pressure just before the occurrence of this dust storm was significant. Satellite observations showed that low-level and convective clouds were beside the dust mass at the time of haboob, while the dry-convective dust storm covered a larger area and dust particles reached at higher altitudes into the atmosphere. WRF-Chem model enabled to identify the dust plumes and simulated satisfactorily the temperature variations and changes in surface pressure during the two dust storms, while larger model discrepancies occurred in representing wind velocity in the case of haboob. The comparison of the model outputs in these two dust storms simulations shows that the performance of the model in simulating the dry-convective dust storm was better than that in haboob. [ABSTRACT FROM AUTHOR]