北京局地降水中地形和边界层辐合线的作用

Effect of Landform and ABL Convergence Line on Local Precipitation in Beijing Areas

利用常规气象资料、雷达、风廓线和地面自动站资料,分析2007年7月两次局地对流天气过程发现,7月13日的局地短时暴雨是由低层东南风遇山脉抬升后产生的;7月10日的局地对流是由边界层辐合线触发形成的。利用风廓线可以判断天气形势和本站气象条件的变化。利用雷达回波图和地面自动站可以识别边界层辐合线。在考虑北京地形的同时,利用雷达严密监视天气,有望提高这类局地对流天气的预报、预警能力。

Based on the conventional weather data, Doppler radar data, wind profile radar data, and automatic weather station data, an analysis is made of two local convective events. The results suggest that the local torrential rain occurred on 13 July 2007 can be attributed to the uplifting of southeast streams at lower levels forced by mountains, and the local convection occurred on 10 July 2007 was triggered by an ABL convergence line. The evolvement of weather conditions can be identified by the wind profile data, and the ABL convergence line by radar echoes and automatic weather station data. Considering the topography in Beijing areas, in combination with the close radar monitoring, the forecasting and warning of local severe convective weather can be improved greatly.