MM5中尺度模式在内蒙古地区一次降水过程中的数值模拟.docVIP

MM5中尺度模式在内蒙古地区一次降水过程中的数值模拟 　　摘要 采用中尺度数值模式MM5，嵌套北京大学和中国科学院人工影响天气所改进后的云微物理过程方案，对2016年4月1―2日发生在内蒙古的降水过程进行模拟与验证，将MM5模式的预报产品与实况资料进行对比发现，MM5模式对内蒙古的天气过程具有一定的预报能力。模拟结果表明：针对受高空低槽影响的内蒙古东部地区的降水过程，综合云和降水预报产品的云系发展演变特征、云系宏观特征、云垂直结构和性质、降水场检验分析，模式较好地预报出了此次降水过程。在云系的发展演变、移动路径、云系垂直结构、降水落区和雨量等方面的预报效果较好，而对内蒙古东部地区云系性质、云系覆盖范围、降水范围与观测结果还有一定差距。其中可降水量的预报能够把握住可降水量的大值区和高值中心等；云水含量和冰晶浓度的预报能给出不同高度层上不同位置上的变化情况；云场的预报所涉及的云的范围、边界形状和趋势预报均同实际情况相符，说明模式对云的预报是可信的；降水的预报与实际情况十分吻合，降水的落区、降水的等级以及降水预报的准确率等均能较好地反映出实际的情况。因此MM5模式用于内蒙古地区的降水预报是可行的，但本文中MM5模式对降水的模拟结果与实况相比仍然偏大，其原因可能与模式的初始场和边界条件的处理有关，以及与所用资料的精度也是有一定联系。 　　关键词 MM5模式；降水预报；数值模拟；内蒙古地区 　　中图分类号 P481 文献标识码 A 文章编号 1007-5739（2016）18-0179-06 　　Abstract The mesoscale numerical model MM5， nested within the cloud microphysics scheme which is an improvement of weather modification made by Beijing University and Chinese Academy. Precipitation happened on April 1st and 2nd 2016 was simulated and tested， compared the forecast product with live data， it was found that MM5 model has certain prediction ability. The simulation results show that the model could forecast this precipitation process after analyzed the characteristics of cloud evolution， moving path， cloud vertical structure and so on， but there was always a certain mismatch between MM5 and observation in cloud properties， cloud coverage， precipitation range. On the whole， MM5 model was credible in weather forecast， because precipitation forecast and the actual situation were very consistent， precipitation area， precipitation grade and accuracy of prediction could reflect the actual situation well. Therefore the MM5 model for precipitation forecast in the area of Inner Mongolia is feasible， but precipitation simulation results obtained by MM5 model is large than that of observation results， which might be related to the treatment of initial field and boundary conditions， as well as the accuracy of the data used. 　　Key words MM5 model；precipitation forecast；numerical simulation；Inner Mongolia 　　内蒙古自治区地处欧