摘要
基于济南S波段双偏振多普勒天气雷达(CINRAD/SA-D)探测资料,并结合区域自动气象站以及常规观测资料,对2020年8月5日和6日山东两次极端强降水风暴环境条件进行对比分析,并重点分析莘县王庄集和兖州大安风暴的双偏振参量特征。结果表明:两次极端强降水天气均具有较高的K指数和较大的对流有效位能(Convective Available Potential Energy,CAPE),湿层厚,垂直风切变中等偏弱,但6日强降水低层垂直风切变和相对风暴螺旋度明显偏强。风暴气流结构有明显差异:王庄集和大安风暴分别表现为倾斜上升和气旋性旋转气流结构,前者风暴顶辐散强而后者较弱,从而导致前者风暴顶高度及差分相移率(K_(DP))柱高度较高。不同高度微物理结构有差异:-10℃层高度之上,两者以固态粒子为主,而王庄集风暴含有更加深厚、丰富的霰粒子,-20~-10℃层还有一定浓度较小的液态粒子;-10℃层高度以下,两者以浓度较高的液态粒子为主,而王庄集风暴含有一定数量的冰相粒子。风暴低层测站周围差分反射率(Z_(DR))、K_(DP)和相关系数(Correlation Coefficient,CC)大致相当,Z_(DR)适中,粒子大小适中,K_(DP)和CC较大,风暴降水主体液态雨滴浓度较高,含水量丰富,从而产生高强度降水。
Based on the Ji’nan S-band dual-polarization Doppler weather radar (CINRAD/SA-D) data,combined with automatic weather station data and conventional observation data,comparative analysis of the environmental conditions are made,and emphasis is laid on the analysis of dual-polarization signatures for the Wangzhuangji storm and Da’an storm,which are short for the two extreme rainfall storms separately occurring at Wangzhuangji county of Shenxian and Da’an county of Yanzhou,Shandong on 5 and 6 August 2020.The results show that:the two extreme heavy rain occurred in the conditions of high K index,large convective available potential energy (CAPE),deep wet layer,and moderately weak vertical wind shear.In contrast,the storm relative helicity (SRH) is evidently larger for the extreme rainfall event on 6 in August.The flow structures of the storms are significantly different:the Wangzhuangji storm tilts upward and intensively diverges at high-level inducing higher storm top and specific differential phase K_(DP)column,while Da’an storm performs as cyclonic rotation with weaker high-level divergence.The microphysical structure varies at different levels:for the both two storms,there are high concentration of solid (liquid) particles separately above (below) -10℃ layer.But Wangzhuangji storm has more abundant graupels abov e-10℃ layer,a few element of liquid particles from -20℃ to -10℃ layer,and a certain amount of ice particles below -10℃ layer.The two storms exhibit comparable dual-polarization characteristics with moderate differential reflectivity Z_(DR),bigger K_(DP)and correlation coefficient (CC) at low-level,which indicate that the rainfall storms constructed with abundant moderate particle size liquid raindrops are rich of water favorable for extreme rainfall.
作者
郭飞燕
刁秀广
褚颖佳
李欣
陆雪
张少博
GUO Feiyan;DIAO Xiuguang;CHU Yingjia;LI Xin;LU Xue;ZHANG Shaobo(Qingdao Engineering Technology Research Center for Meteorological Disaster Prevention/Qingdao Meteorology Bureau,Qingdao 266003,China;Shandong Meteorological Observatory,Ji'nan 250031,China;Ji'nan Meteorology Bureau of Shandong,Ji'nan 250102,China)
出处
《干旱气象》
2023年第1期103-113,122,共12页
Journal of Arid Meteorology
基金
山东省自然科学基金项目(ZR2021QD028,ZR2021MD062)
山东省气象局科研项目(2019sdqxz01,SDYBY2017-05,SDYBY2020-04)
山东省精准预报技术创新团队共同资助。