利用FY2G卫星云图、雷达资料、自动雨量站等观测资料和NCEP/NCAR逐6 h 2.5°×2.5°再分析资料对2018年6月22日~25日云南省文山州大暴雨天气过程进行分析。结果表明,此次暴雨过程的主要影响系统是两高之间的辐合区和低涡切...利用FY2G卫星云图、雷达资料、自动雨量站等观测资料和NCEP/NCAR逐6 h 2.5°×2.5°再分析资料对2018年6月22日~25日云南省文山州大暴雨天气过程进行分析。结果表明,此次暴雨过程的主要影响系统是两高之间的辐合区和低涡切变线。由于高原槽不断东移加深,孟湾低压与印度半岛低压系统合并加强,西太平洋副热带高压加强西伸,文山州受强偏南气流影响,产生强烈水汽辐合,造成持续强降水;不断有对流单体发展且合并到大的对流云团中,有较大范围的对流云团持续影响是此次大暴雨的主要云图特征;雷达上持续存在“S”型径向速度图,且存在较强降水回波在文山附近生消发展,造成明显的“列车效应”。展开更多
Using mesoscale numerical model WRFV3.7,simulation tests of a low-vortex rainstorm were carried out in Langfang area,and simulation results of three boundary layer parameterization schemes(MYJ,YSU,ACM2)were contrasted...Using mesoscale numerical model WRFV3.7,simulation tests of a low-vortex rainstorm were carried out in Langfang area,and simulation results of three boundary layer parameterization schemes(MYJ,YSU,ACM2)were contrasted.The results showed that the rainstorm in Langfang area had better dynamic condition.By the influence of northeast cold vortex,cold vortex at high altitude cooperated with the surface wind speed convergence,which provided better dynamic condition for strong convective rainfall.Three boundary layer parameterization schemes all simulated surface wind speed convergence of rainstorm center.Simulation results of 24-h rainfall distribution showed that the simulation of YSU scheme was better than ACM2 and MYJ.The simulation results of flow field and temperature field also verified that YSU scheme was better than other schemes.展开更多
分析2011年2月25—27日张家口市降雪天气过程的高空天气形势,结果表明,降雪期间500 h Pa高空在新疆北部是一个深厚的低涡系统,冷低涡不断分裂出小股冷空气东移影响张家口市;850 h Pa低涡、暖舌、切变线和低空急流为此次长时间降雪提供...分析2011年2月25—27日张家口市降雪天气过程的高空天气形势,结果表明,降雪期间500 h Pa高空在新疆北部是一个深厚的低涡系统,冷低涡不断分裂出小股冷空气东移影响张家口市;850 h Pa低涡、暖舌、切变线和低空急流为此次长时间降雪提供了必要条件;26日08：00 850 h Pa张家口市西部的切变线,是造成降雪的关键性动力系统;25—28日张家口市上空850~700 h Pa相对湿度大值区的出现时间与降水时间相吻合,较好的中低层湿度状况为降雪提供了原材料。展开更多
文摘利用FY2G卫星云图、雷达资料、自动雨量站等观测资料和NCEP/NCAR逐6 h 2.5°×2.5°再分析资料对2018年6月22日~25日云南省文山州大暴雨天气过程进行分析。结果表明,此次暴雨过程的主要影响系统是两高之间的辐合区和低涡切变线。由于高原槽不断东移加深,孟湾低压与印度半岛低压系统合并加强,西太平洋副热带高压加强西伸,文山州受强偏南气流影响,产生强烈水汽辐合,造成持续强降水;不断有对流单体发展且合并到大的对流云团中,有较大范围的对流云团持续影响是此次大暴雨的主要云图特征;雷达上持续存在“S”型径向速度图,且存在较强降水回波在文山附近生消发展,造成明显的“列车效应”。
文摘Using mesoscale numerical model WRFV3.7,simulation tests of a low-vortex rainstorm were carried out in Langfang area,and simulation results of three boundary layer parameterization schemes(MYJ,YSU,ACM2)were contrasted.The results showed that the rainstorm in Langfang area had better dynamic condition.By the influence of northeast cold vortex,cold vortex at high altitude cooperated with the surface wind speed convergence,which provided better dynamic condition for strong convective rainfall.Three boundary layer parameterization schemes all simulated surface wind speed convergence of rainstorm center.Simulation results of 24-h rainfall distribution showed that the simulation of YSU scheme was better than ACM2 and MYJ.The simulation results of flow field and temperature field also verified that YSU scheme was better than other schemes.
文摘分析2011年2月25—27日张家口市降雪天气过程的高空天气形势,结果表明,降雪期间500 h Pa高空在新疆北部是一个深厚的低涡系统,冷低涡不断分裂出小股冷空气东移影响张家口市;850 h Pa低涡、暖舌、切变线和低空急流为此次长时间降雪提供了必要条件;26日08：00 850 h Pa张家口市西部的切变线,是造成降雪的关键性动力系统;25—28日张家口市上空850~700 h Pa相对湿度大值区的出现时间与降水时间相吻合,较好的中低层湿度状况为降雪提供了原材料。
