Case studies of hailstorms in Shandong Province using hail size discrimination algorithm based on dual polarimetric parameters  

作　　者：Juxiu WU Fan XIA Jiawen PAN Guanglu HAN Weijia SUN Chen GU 

机构地区：[1]Shandong Meteorological Engineering Technology Center,Jinan 250031,China [2]Meteorological Sciences Institute of Shandong,Jinan 250031,China [3]Xiamen Meteorological Bureau,Xiamen 361012,China [4]College of Geodesy and Geomatics,Shandong University of Science and Technology,Qingdao 266590,China [5]Key Laboratory for Meteorological Disaster Prevention and Mitigation of Shandong,Jinan 250031,China [6]Xiamen Key Laboratory of Straits Meteorology,Xiamen 361012,China [7]Changdao National Climate Observatory,Changdao 265800,China

出　　处：《Frontiers of Earth Science》2024年第4期752-762,共11页地球科学前沿(英文版)

基　　金：supported by the Shandong Provincial Natural Science Foundation of China(Nos.ZR2020MD052 and ZR2022MD072);the National Natural Science Foundation of China(Grant No.41675029);East China Regional Collaborative Innovation Fund for Meteorological Science and Technology(No.QYHZ202101);Project of Xiamen Bureau of Science and Technology(No.3502Z20214ZD4005);Key Project of Shandong Meteorological Bureau(Nos.2021SDQXZ09 and SDLD2022-02)。

摘　　要：The hail size discrimination algorithm(HSDA)and its capacity to identify hail in Shandong Province are analyzed to satisfy the localized requirement by China’s S-band dual-polarization radars.A modified HSDA is obtained by using optimized membership function thresholds based on the statistics of Shandong hail data.The results are verified by a supercell storm process.1)The modified HSDA improves the identification of large hail and giant hail.The results are consistent with the analysis of the scattering and polarization parameter characteristics of different-size hails,the dynamic and microphysical characteristics for supercell,and the real situation.2)The horizontal and vertical hail-size distribution characteristics are consistent with the analysis about the growth process of larger hails and the precipitation particles filtering mechanisms in supercells.Small hail first forms at the suspension echo,then is injected into the larger hail growth area above the bounded weak echo area driven by updrafts,colliding with the abundant supercooled water in the KDP column.Finally,large hail and giant hail fall near the direction of the updrafts to form a strong echo wall,and giant hail falls 6–12 km from the central updraft.3)The maxima of the ZDR and KDP columns can be used to predict the hail-growth trend,which exceeds the−20°C isotherm for the heavy-hail growth stage at high-altitude in the supercell storm.When hail falls to the ground,the ZDR column shortens and the KDP column disappears,which provides the observation basis from polarimetric radars for the consumption of supercooled water by hail growth.

关 键 词：polarimetric parameters/hail size discrimination/membership function/giant hail 

分 类 号：F42[经济管理—产业经济]