Numerical study of a very intensive eastern Mediterranean dust storm, 13–16 March 1998

[1] Presented herein is an analysis of an exceptionally intensive central and eastern Mediterranean dust intrusion of 15–16 March, 1998. The intrusion has been associated with development of an intense cyclone over Africa. The weather and dust development processes were simulated with the Eta weather and dust prediction model. Also presented is a comparison of the model results with the Total Ozone Mass Spectrometer Aerosol Index (TOMS AI) pictures as well as with those of the surface and weather observations. The roles of the main processes responsible for the dust plume development and associated dust intrusion to the eastern Mediterranean (EM) are studied. The observation data as well as the model-simulated parameters are jointly analyzed. The analysis also includes the data from the back-trajectory computations. With the aid of the model-produced dust profiles we studied the significant variation in the altitudes of the dust layers within the cyclone sectors. In the warm sector of the cyclone located over the Mediterranean Sea the dust layer extended up to 8–10 km. Relatively low dust concentration values were found here. In the area of the cold front over Africa the dust was restricted to the lower troposphere and the planetary boundary layer. Here the model simulated high values of the dust concentrations. The sharp TOMS AI increase over Israel and the eastern Mediterranean up to 5.0 units, further away from the dust sources, is explained by the strong winds, by the increased cyclone convergence, and the formation of a two-layer dust plume.