The possible impact of the circumglobal wave train on the wet season dust storm activity over the northern Arabian Peninsula

Abstract

This study examines the influence of mid-latitude circulation on the wet season (October–May) Dust Storm Activity (DSA) over the northern Arabian Peninsula for the period of 1983–2013, using observational and reanalysis gridded datasets. Dusty and clear days composites of the 200 hPa geopotential height anomalies reveal a pattern in the upper-levels which is strongly correlated with the mid-latitude circumglobal wave train (CGT) and exists 3 days prior to the outbreak of dust storms. The regional surface conditions (such as the mean sea level pressure; low-level temperature and winds, etc.) that favor the DSA over the northern Arabian Peninsula display significant correlations with the CGT on intraseasonal time scale. A time-lagged analysis reveals that the eastward propagating CGT influences the surface pressure over the northern Arabian Peninsula and adjacent areas—hence the DSA. The DSA over the northern Arabian Peninsula is found to be more frequent during the positive phase of the North Atlantic Oscillation (NAO) and the cold phase of the El Niño–Southern Oscillation (La Niña), and less frequent during the negative phase of NAO and the warm phase of the El Niño–Southern Oscillation (El Niño).