Analyzing two decades of dust events on the Southern Great Plains region of West Texas

Abstract

Blowing dust is a weather phenomenon common in many locations around the world. During these dust events, particle concentration increases causing visibilities to decrease, sometimes even down to 0, increasing chances of travel accidents and also cause health complications. The Southern Great Plains region of West Texas experiences many dust events annually. In this study, 420 dust events (including widespread dust, blowing dust, and dust storms) were analyzed over 2000–2019. PM2.5 concentrations during these dust events showed a unimodal diurnal distribution with a peak in the afternoon. Most of the dust events occur during the spring and summer months and La Niña period. Separation of these events based on their meteorological cause (convective and synoptic), found that most (66.4%) were caused by a synoptic disturbance, mainly a cold front. Synoptic dust events occurred all year round, but mainly during spring (March–April), while convective, which accounts for 31% of the dust events, had the highest occurrence during May–July. Most of the synoptic events occurred in the afternoon while convective were in the evening. Meteorological comparison between convective and synoptic showed that synoptic events were associated with lower temperatures and relative humidity values, but with higher wind speeds and gusts. Comparison of PM2.5 concentrations found a different impact on air quality. Out of all the synoptic dust events, only 12 events exceeded the EPA recommended PM2.5 daily threshold values, while none of the convective dust events were above that threshold, perhaps due to their short duration (less than an hour).