利用中尺度天气模式WRF V2.2进行了两组风场的敏感性试验,分别模拟了西风与季风变化对黑河流域降水的影响.通过对大气环流、水汽输送、水汽辐合以及垂直上升运动的分析得出以下结论:西风与季风对黑河流域降水的影响方式不同,西风带直接作用于黑河流域,影响其降水,而季风则是通过对西风的调整间接影响黑河流域降水;西风与季风变化对黑河流域降水的影响范围不同,西风增强后,黑河流域南部山区降水落区西移,降水增加,最大值中心偏西北;季风增强后,黑河流域南部山区降水落区向东南移,降水增加,最大值中心偏东南.与其它量相比,黑河流域降水与垂直速度的对应关系最好.
In this article,two sensitivity simulations for the effects of the westerly and monsoon on precipitation in the Heihe River basin are conducted by using the new generation mesoscale weather model WRF(Weather Research and Forecast model)version 2.2.The horizontal current field,water vapor transportation,and vertical velocity are analyzed.It is found that the effects of westerly and monsoon are different.The westerly has a direct influence on precipitation in the Heihe River basin,while the monsoon has an indirect effect,through adjusting the westerly.The affecting area and intensity are also different.When westerly strengthens,precipitation in the southwest mountainous area increases and moves westward,with a maximum precipitation center moving northwestward.When monsoon strengthens,precipitation in the basin moves eastward and increases,with a maximum precipitation center shifts to southeast.Compared with other meteorology factors analyzed above,the vertical velocity shows best relationship with precipitation.