Global aeolian dust variations and trends: a revisit of dustfrequency and visibility observations from surface weather stations

Abstract:

Synoptic weather observations from meteorological stations provide the longest sub-daily instrumental record of global dust processes near source and in downwind areas, and has unique advantage for characterizing interannual and decadal dust variations compared to passive satellite remote sensing, which has a relatively short record length (~20 yrs), low sampling frequency (1-2 times per day), and limited coverage over dust source areas (due to high surface reflectance). The long-term station observations of dust event occurrence and visibility, however, are subject to data discontinuity and inconsistency due to changes in station coverage, dust weather definitions, observation schedule, and report protocols. The inhomogeneous data quality, combined with large data volume, present a major barrier for most end users in their attempt for long-term dust analysis. This presentation will discuss the dust record quality issues in the NOAA Integrated Station Database (ISD), and a number of data screening and quality checks designed to create a homogenized dust record spanning more than 50 yrs. The station-based dust dataset will be evaluated by comparing with multiple satellite- and model-based dust aerosol climatology. Main results will be presented on the global decadal mean dust pattern and interannual variability, followed by investigations of the regional heterogeneity in recent dust trends and driving factors for the world’s most prominent dust source areas.