基于NCEP资料新疆降水转化率的研究

Analysis of precipitation conversion in Xinjiang based on NCEP data

大气可降水量是降水形成的基础,二者空间上的差异特征是水资源研究的焦点之一。本文针对新疆降水时空差异大的特点,以降水转化率为切入点,基于2001-2010年NCEP/NCAR再分析资料和同期新疆52个气象站的月降水量资料,采用整层大气可降水量计算公式计算了新疆大气可降水量和降水转化率,对新疆降水转化率的空间分布特征进行了分析。分析结果表明,新疆的大气可降水量沿盆地向山区递减,与降水转化率的分布大致相反。降水转化率的高值区主要位于天山山区中段至西段、昆仑山山区西段,低值区主要位于准葛尔盆地和塔里木盆地。大气可降水量及降水转化率值年内变化明显,夏季转化率最大,春秋季次之,冬季最小。研究结果可为分析新疆地形对降水的影响机制提供参考。

Atmospheric precipitable water（APW） plays an important role in precipitation formation. There are great differences in space for precipitation. Based on monthly NCEP/NCAR reanalysis data and observation data in 52 meteorological stations during 2001- 2010, the spatial distribution of precipitation conversion was analyzed. Then the spatial distributions of APW and precipitation conversion efficiency（PCE） in Xinjiang were investigated by APW method. Lastly, their spatial characteristics were analyzed. The result indicates that the APW in Xinjiang decreases gradually from basins to mountains, which is opposite to PCE. The high values of PCE mainly appear in the middle- western Tianshan Mountains and western Korum Mountain. The low values mainly appear in Junggar Basin and Tarim Basin. There is significant seasonal variation during the year. The maximum of PCE appears in summer, and the second one is in autumn, the followings are in spring and winter. Results of this research could provide reference for the impact of topographical mechanism on precipitation in Xinjiang.