玛曲一次强降水过程的风廓线演变特征

Wind profiler evolution charcteristics of the precipitation weather process in Maqu

利用2011年8月18日甘南玛曲风廓线仪探测强降水过程的资料,分析了风廓线雷达探测的强信号与降水强度的对应关系:在降水情况下,风廓线雷达探测到约小于4m/s的垂直速度反映了降水的开始和结束,且垂直速度越小降水越强;同时大气折射率结构常数与降水强度有很好的对应关系,-110db的大气折射率结构常数的开始和结束反映了降水的始终,而且风廓线雷达探测到的大气折射率结构常数对降水持续时间和降水强度的敏感程度比垂直速度更高。由于降水时降水粒子的下落速度所造成的负垂直速度与降水强度的对应关系同时也反映了降水粒子的密度。另外,风廓线仪探测到的垂直速度数值大小随高度的波动反映了大气中垂直热交换的强度,因而它有可能成为判断对流发展强弱的一个重要指标。

The corresponding relationship between precipitation and the strong signal detected by wind profiler radar（WPR） on 18th August in Maqu was analyzed.When it rained,the vertical velocity detected by WPR less than 4m/s reflected the start and end of the rainfull and the smaller the vertical velocity,the stronger the precipitation.There was also perfect correlation between the refractive index structure constant and the precipitation,the start and end of the refractive index structure constant which was-110db also reflected the start and end of the rainfull and the refractive index structure constant was more sensitive to the rainfull＇s duration and intensity than the vertical velocity.The relationship between the negative vertical velocity caused by the falling speed of the raindrop and the precipitation intensity also reflected the raindrop＇s density.Because the values of the vertical velocity detected by WPR changing with altitude reflected the intensity of the vertical heat exchange in the atmosphere,so the vertical velocity should likely become an important index to estimate the convection＇s strength.