Dynamic and synoptic study of spring dust storms over northern Saudi Arabia

Abstract

The synoptic and dynamic characteristics of dust storm events over northern Saudi Arabia were studied during the spring season from 1978 to 2008 using surface dust storm observations from 11 stations and meteorological data from the NCEP/NCAR reanalysis dataset. Two-day dust-free periods were selected before and after each event to represent the pre- and post-event stages, respectively. The synoptic study identified two synoptic systems associated with dust events, i.e., frontal systems and shamal systems, and these systems were associated with increases in the pressure and temperature gradient over the northern Arabian Peninsula (AP) and an eastward shift in the maximum wind as a dust storm event progressed from the pre- to post-event stages. The dynamic study also showed that during the pre-event stage, the atmosphere was baroclinic and featured dynamic disturbances by frontal systems. Additionally, frontal systems resulted in slightly greater intensification than the shamal systems. Moreover, the dynamic study demonstrated that the kinetic energy (KE) shifted eastward and the available potential energy (APE) shifted northward through a series of regions importing and exporting KE and APE. The vertical profile of the average energy area indicated that the main layer in which sensible heat was converted into KE was located above the dust cloud.