塔克拉玛干沙漠区域性与塔中局地性沙尘暴特征比较

Characteristics Analysis of Regional and Local Sandstorm over the Hinterland of Taklimakan Desert:Taking Tazhong as Example

利用2005—2014年塔克拉玛干沙漠腹地塔中及沙漠周边15个气象台站沙尘暴资料,根据塔中发生沙尘暴时周边台站响应数和范围,划分出影响塔中的区域性与局地性沙尘暴,分析沙尘暴的持续时间、能见度、类型、时间变化等特征。研究结果表明:(1)10 a塔中发生沙尘暴日数为170 d比沙漠南北缘14个气象台站的平均值高,比肖塘少,其中区域性沙尘暴日数为80 d,局地性沙尘暴日数为90d;(2)总体上,塔中区域性沙尘暴的持续时间比局地性沙尘暴长,能见度比局地性沙尘暴低;(3)区域性沙尘暴可按盛行风向分为5类,这5类沙尘暴的季节分布不均匀;(4)区域性与局地性沙尘暴10 a波动增长,区域性沙尘暴多发生在春季,局地性沙尘暴多发生在夏季,区域性沙尘暴的年际和年内变差系数都小于局地性沙尘暴,区域性与局地性沙尘暴白天发生频率大于夜晚,局地性沙尘暴主要发生在午后,区域性沙尘暴各个时间段均可发生。

Based on the observed sandstorm data during 2005-2014 from Tazhong station, which located in the hinterland of Taklimakan Desert, and other 15 weather stations that surrounded the desert, the regional and local sandstorms are classified by using the response data of 15 surrounding stations when sandstorm occurs at the Tazhong station, then, the sandstorm characteristics of duration, visibility, type and temporal variation are analyzed. The results show：（1）The days of sandstorm occurred at the Tazhong was 170 d/10 a, including 80 days of the local sandstorm and 90 days of the regional sandstorm, the sandstorm occurred days is higher than that days of the surrounding 15 stations except Xiaotang, thus, it is only less than that of the Xiaotang station;（2） In general, the duration of the regional sandstorm is longer than that of the local sandstorm, and the visibility of the regional sandstorm is below than that of the local sandstorm;（3）The regional sandstorm is classified into 5 types according to itself prevailing wind direction, every type sandstorm demonstrates seasonal uneven distribution;（4）The days of the regional and local sandstorm were increased with fluctuation in the past 10 a. The regional sandstorm appears more in spring while the local one occurs more in summer, the coefficient of variation of the local sandstorm is less than the regional one in annual and inter-annual. The frequencies of both the regional and local sandstorm occurred at daytime is more than that at nighttime. The local sandstorm occurs mainly at afternoon, however, the regional sandstorm appears at any time.