Applying a dust index over North China and evaluating the contribution of potential factors to its distribution

Abstract

The Taklimakan and Gobi Deserts are the largest desert regions in North China. Correlations between the incidence of dust events in these deserts and their climatic parameters have not yet been fully described. In this study, a dust index was defined utilizing dust event records, including dust storm, blowing dust, and floating dust events, from 1,731 observation stations in North China during the period of 1961-2014. The incidence of dust events decreased markedly across North China during that period, especially in the Taklimakan Desert region (TDR) and Gobi Desert region (GDR). The major factors contributing to this trend were evaluated in this study, including meteorological factors, land surface conditions, atmospheric circulation patterns, and oceanic oscillations. The results indicate that meteorological factors constituted the dominant contribution, accounting for 62.5% and 58.0% of the reduction in dust event incidence in the TDR and GDR, respectively, with lower wind speeds playing an especially important role in the latter. Oceanic oscillations were the next most significant contributor, leading to dust event reductions of 20.1% and 32.4% in the TDR and GDR, respectively. Increased normalized difference vegetation index values were also significantly related to the dust event decline observed in the TDR.