Abstract
Dust events frequently occur in Tarim Basin (TB), China. However, research is scarce on the variation characteristics of sand–dust, floating dust, sand blowing, and sandstorms in the mountains, oases, and deserts in TB. Therefore, we conducted in–depth studies on the distributions and variations of dust events in TB. The results indicate that dust events tend to increase from south to north. The yearly sand–dust event occurrence rate trend is deserts > oases > mountainous regions. In spring, sand–dust, floating dust, sand blowing, and sandstorm days account for 35.9 %, 36.0 %, 38.5 %, and 47.1 % of the whole year, while in summer they account for 33.6 %, 33.5 %, 43.8 %, and 60.3 % of the whole year. From 1961 to 2015, most stations (annual average > 30 stations) showed a downward linear trend in sand dust, floating dust, sand blowing, and sandstorms in TB. All types of sand–dust events in mountains and oases decreased substantially after 1975 to 1978. In spring and summer, the downward dust trends are the most obvious, which the largest annual average downward linear trend rates of floating dust, sand blowing, and sandstorms are -0.33 d/yr (QM station), -0.21 d/yr (TGLK station), and -11 d/yr (KP station), respectively, in spring, and -0.28 d/yr (QM station), -0.17 d/yr (TGLK station), and -0.14 d/yr (KP station), respectively, in summer. It is found that the decreasing and increasing trends of floating dust are the most obvious during sand–dust events. There is a significant positive correlation between wind speed and relative humidity in mountains, and a significant positive correlation between wind speed in oases.
Interannual and seasonal variations of sand-dust events in Tarim Basin, China