2022年冬奥会期间北京一次强降雪过程平原和山区云微物理特征差异的数值模拟  

Numerical Simulation on the Difference of the Cloud Microphysical Characteristics between Plain and Mountainous Areas in a Heavy Snowfall Process in Beijing during the 2022 Winter Olympic Games

作　　者：许丽人 蔡军 李玉鹏 平凡[3,6] 李吉 XU Liren;CAI Jun;LI Yupeng;PING Fan;LI Ji(Beijing Institute of Applied Meteorology,Beijing 100029;Aerospace Information Research Institute,Chinese Academy of Science,Beijing 100094;Laboratory of Cloud–Precipitation Physics and Severe Storms(LACS),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;University of Chinese Academy of Sciences,Beijing 100049;Key Laboratory of Changbai Mountain Meteorology and Climate Change,Institute of Meteorological Sciences of Jilin Province,Changchun 130062;School of Remote Sensing and Geomatics Engineering,Nanjing University of Information Science and Technology,Nanjing 210044;Meteorological Observatory of Jilin Province,Changchun 130062)

机构地区：[1]北京应用气象研究所,北京100029 [2]中国科学院空天信息创新研究院,北京100094 [3]中国科学院大气物理研究所云降水物理与强风暴重点实验室(LACS),北京100029 [4]中国科学院大学,北京100049 [5]吉林省气象科学研究所长白山气象与气候变化重点实验室,长春130062 [6]南京信息工程大学遥感与测绘工程学院,南京210044 [7]吉林省气象台,长春130062

出　　处：《大气科学》2024年第5期1762-1782,共21页Chinese Journal of Atmospheric Sciences

基　　金：河北省技术创新引导计划科技冬奥专项19975414D;吉林省科技发展计划项目20180201035SF;中国气象局创新发展专项CXFZ2022J007;吉林省气象局科研课题201906。

摘　　要：本文运用WRF4.2中尺度数值模式模拟了2022年2月12~13日北京地区的一次强降雪过程,模式较好地再现了此次强降雪的时空演变特征。在此基础上,对比分析北部山区和南部平原地区动力、热力以及云微物理过程差异,探讨了复杂地形影响降雪的可能机制。结果表明:本次降水过程以固态降水为主,同时存在着显著的条件对称不稳定特征。模拟结果表明山区的降水要强于平原地区。山区和平原地区的动力和热力因子的对比分析表明,地形的存在使山区低层的散度、涡度以及垂直速度明显强于平原地区,位温扰动也更强,山区上空云体发展更为旺盛,且山区上空为水汽的汇区,水汽的相变过程更为活跃。山区和平原地区水凝物粒子虽然都以冰晶和雪两类粒子为主,但山区上空的冰晶和雪含量更多。降雪云内主要的水凝物转换过程为:冰晶的核化、冰晶的凝华增长、冰晶向雪的自动转化、雪收集冰晶增长、雪的凝华增长以及发生在近地层附近的冰晶和雪晶的升华过程。近地层水汽条件的差异使平原地区近地面附近冰晶和雪的升华过程更强。1.5 km高度以下近地层附近存在由云滴活化产生的过冷云水,过冷云水的存在一定程度促进了冰晶和雪的凝华增长,以及雪的凇附过程。The Weather Research and Forecasting(WRF 4.2)mesoscale numerical weather prediction model was used to simulate a heavy snowfall in Beijing from 12 to 13 February 2022,and the spatial and temporal evolution characteristics of the snowfall were well reproduced.Based on the simulation data,differences in dynamic,thermal,and cloud microphysical processes between the northern mountainous and southern plain areas were analyzed,and the possible impact of complex terrain on the snowfall process was discussed.Precipitation particles were ice-phase particles accompanied by significant conditional symmetric instability in the atmosphere.The simulation results show that precipitation was stronger in the mountainous areas than in the plain areas.A comparison of dynamic and thermal conditions between the mountainous and plain areas shows that the divergence and vorticity fields in the mountainous area were stronger due to the existence of topography.These areas also exhibited higher vertical velocities and stronger perturbation potential temperatures than the plain area.Cloud development was more vigorous over the mountainous areas,characterized by dominant water vapor sink regions where the phase transition of water vapor was more active.Although ice crystals and snow were the main hydrometeor particles in the mountainous and plain areas,the contents of ice crystals and snow were higher in the mountainous areas.The dominant conversion processes for ice crystals in clouds included the nucleation and deposition of ice crystals,autoconversion of ice crystals to snow,accretion of ice crystals by snow,deposition of snow crystals,and sublimation of ice and snow crystals near the surface.The difference in nearsurface water vapor conditions led to a stronger sublimation process of ice crystals and snow in the plain areas.In addition,the occurrence of supercooled cloud water generated by the activation of cloud droplets close to the near-surface layer below 1.5 km altitude promoted the deposition of ice crystals and snow and the accre

关 键 词：地形作用 强降雪 云微物理特征 数值模拟 

分 类 号：P458[天文地球—大气科学及气象学]