Sensitivity Study of Daily Dust Forecast over the Mena Region Using the RegCM4.4 Model

Abstract

Dust storms are one of the most frequent weather phenomena in the Middle East and North Africa (MENA) region. Therefore, the daily forecast of dust events is vital for different sectors. Many regional models can be used to forecast atmospheric dust storms. Here, the ICTP regional climate model (RegCM4) was used to simulate atmospheric dust emission, transportation, and deposition, using the optical properties of dust particles, over the MENA region. In the current work, the dust optical depth (DOD) obtained using RegCM4 was compared with the aerosol optical depth (AOD) measured by AERONET at different stations and by MODIS. In the first experiment, two datasets (NCEP/GFS and ERA-Interim) for the meteorological initial and boundary conditions have been used, whereas in the second experiment, GFS with two dust emission schemes have been used. In the last experiment, GFS with two values of the erodibility factor (1 and 0.5) have been used. The RegCM4 forecast with GFS and the first dust emission scheme provided higher values of DOD than AERONET. However, when using the reanalysis data of ERA-Interim or the second dust emission scheme, there was no significant difference, but the erodibility factor decreases led to a reduction in the overestimated values.

Keywords

• dust
• RegCM4
• GFS
• ERA-Interim
• AOD
• erodibility factor