2016年7月24日宁夏中北部大到暴雨降水物理量特征分析  

Physical characteristics analysis on the different magnitude of rainfall in Ningxia occurring on 24 July 2016

作　　者：李婷[1,2,3] 陈豫英[1,2,3] 谭志强 何劲夫[1,2,3] 

机构地区：[1]中国气象局旱区特色农业气象灾害监测预警与风险管理重点实验室,宁夏银川750002 [2]宁夏气象防灾减灾重点实验室,宁夏银川750002 [3]宁夏气象台,宁夏银川750002

出　　处：《宁夏工程技术》2017年第4期299-302,308,共5页Ningxia Engineering Technology

摘　　要：2016年7月23日夜间到24日白天,宁夏中北部出现大到暴雨量级强降水,此次降水范围广、强降水区域集中、小时雨强强。利用宁夏加密自动站观测资料、FNL1°×1°格点再分析资料等对2016年7月23日夜间到24日白天区域性强降水天气过程的环流背景,水汽、动力、不稳定能量等方面进行分析。结果表明,副热带高压北抬过程中,其外围的低涡切变线与西风槽系统相互作用产生宁夏中北部地区强降水;降水时间与700 hPa系统的移入移出有较好对应关系,强降水落区位于低涡右前侧和低空急流左侧。分析各量级降水物理量特征发现,暴雨站整层水汽饱和,对流层低层700 hPa有强度大于6×10^(-5)s^(-1)正涡度中心,500 hPa有强度小于0.7 Pa/s垂直上升运动中心;大雨和中雨站对流层高层为干冷空气,对流层低层的辐合强度和对流层高层的辐散强度基本一致,对流层低层涡度小于3×10^(-5)s^(-1),且垂直上升运动中心位置位于500 hPa以上;小雨站对流层中低层的水汽条件较差,K指数在降水发生过程中基本没变化,且对流层高层辐散强于对流层低层辐合。The characteristics of synoptic circulations, water vapor, energy parameter related to the formation of the precipitation happened in Ningxia on 24 th July 2016 were analyzed with Ningxia automatic station observation data and FNL 1 ° ×1° interval reanalysis data. The results showed that the severe rainfall in north-central of Ningxia was generated by the interaction among the low vortex shear line and the westerly trough. The start/end time of the rainfall corresponded well to systems on the 700 hPa and heavy rainfall occurred on the right side of the low vortex and the left side of the low level jet. The water vapor over the rainstorm station was saturated. There was a positive vortex center with strength greater than 6×10^（-5） s^（-1） on the lower troposphere of 700 hPa and there was a ascending motion with the intensity less than 0.7 Pa/s on500 hPa. There was a cold trough over the heavy and the moderate rain station and the intensity was almost the same between the low level and the high level with the vorticity less than 3 ×10^（-5） s^（-1）. And the center of the ascending motion was above 500 hPa. The water vapor over the light rain station was poor, K index was stable and the intensity of the high level negative convergence was greater than the low level positive convergence.

关 键 词：强降水 环流形势 物理量特征 

分 类 号：P458[天文地球—大气科学及气象学]