青藏高原及其周边区域沙尘天气的时空分布特征

基于站点观测的沙尘暴数据和卫星遥感(FY-3A)的沙尘数据,分析了青藏高原及塔里木盆地-河西走廊沙尘天气的时空分布特征。结果表明:在空间分布上,沙尘天气发生的次数和强度自塔里木盆地-河西走廊往青藏高原的东南方向递减。季节变化上,沙尘暴在青藏高原主要发生在冬、春季,而在塔里木盆地-河西走廊主要发生在春、夏季,这主要是由于地表大风中心在3月北移、10月南移;FY-3A反演的沙尘天气在两个区域均主要发生在冬、春季,发生强度与观测结果在季节变化上也存在差异。在1980-2007年,青藏高原的沙尘暴发生次数和强度上均呈减弱趋势,塔里木盆地-河西走廊的沙尘暴发生次数减弱而强度增强。

Spatial and Seasonal Distributions of Sand Dusts in Qinghai-Tibet Plateau and Its Surrounding Areas

In-situ observed sand-dust storm data and FY-3A dust storm monitoring data were used to analyze the spatial and seasonal distribution of sand-dust weather in Qinghai-Tibet Plateau. Results show that the occurrence frequency and strength of sand-dust weather decrease from the TH to the southeastern QTP. Seasonally, observations show that the QTP has more sand-dust storms in spring and winter, while the TH has more sand-dust storms in spring and summer, mainly because the near-surface high wind speed moves north in March and then moves south in October. However, FY-3A dust storm data show that there is more sand-dust weather in winter and spring for both regions, its occurrence strength of sand-dust weather is also different from the observations seasonally. In 1980-2007, the occurrence frequency of sand-dust storms reduces for most stations in both QTP and TH significantly, but their occurrence strength decreases in QTP while increases in TH.