地面资料同化的飑线数值模拟及中尺度特征分析

Assimilation of surface observation data in numerical simulation of a squall line and mesoscale characteristics analysis

为了揭示飑线的中尺度精细结构特征,针对2006年6月25日发生在河套地区的一次飑线天气过程,在分析其过程天气背景的基础上,使用WRF模式和三维变分资料同化技术,对此次飑线过程中的地面常规观测和自动气象站加密观测资料进行了同化试验。结果表明:同化地面观测资料可以有效地提高模式对飑线这样的强对流天气系统模拟效果,输出的高分辨率模式资料可以更加精细地刻画出中纬度飑线中尺度结构特征。

In order to reveal the fine-scale structural characteristics of a squall line, taking a squall line happened in the Loop area on June 25, 2006 as an example, on the basis of having analyzed the weather background of the process, this paper makes use of WRF model and three-dimensional variational data assimilation technology and conducts an assimilation test, the conventional ground and enhanced automatic weather station observational data during the squall process have been assimilated into the model for the assimilation test. The results show that the assimilation of ground observational data can be effective in improving the simulation results of model in simulating strong convective weather systems like the squall line, and that the output of high-resolution data of mode can result in more precise characterization of meso-scale structural characteristics of a squall line in the mid-latitude.