An Extreme Gale Event in East China under the Arctic Potential Vorticity Anomaly through the Northeast China Cold Vortex  

作　　者：Wei TAO Linlin ZHENG Ying HAO Gaoping LIU 

机构地区：[1]Anhui Meteorology Observatory,Hefei 230031,China

出　　处：《Advances in Atmospheric Sciences》2023年第12期2169-2182,共14页大气科学进展（英文版）

基　　金：supported by the China National Science Foundation (Grant No. 41705029);Anhui Joint Foundation (Grant No.2208085UQ11);China Meteorological Administration special grants on innovation and development (Grant No. CXFZ2023J017);China Meteorological Administration special grants on decision-making meteorological service (Grant No. JCZX2022005);support from the innovation team at Anhui Meteorological Bureau

摘　　要：Arctic changes influence not only temperature and precipitation in the midlatitudes but also contribute to severe convection.This study investigates an extreme gale event that occurred on 30 April 2021 in East China and was forced by an Arctic potential vorticity(PV)anomaly intrusion.Temperature advection steered by storms contributed to the equatorward propagation of Arctic high PV,forming the Northeast China cold vortex(NCCV).At the upper levels,a PV southward intrusion guided the combination of the polar jet and the subtropical jet,providing strong vertical wind shear and downward momentum transportation to the event.The PV anomaly cooled the upper troposphere and the northern part of East China,whereas the lower levels over southern East China were dominated by local warm air,thus establishing strong instability and baroclinicity.In addition,the entrainment of Arctic dry air strengthened the surface pressure gradient by evaporation cooling.Capturing the above mechanism has the potential to improve convective weather forecasts under climate change.This study suggests that the more frequent NCCV-induced gale events in recent years are partly due to high-latitude waviness and storm activities,and this hypothesis needs to be investigated using more cases.

关 键 词：PV anomaly Arctic storm Northeast China cold vortex convection extreme gale 

分 类 号：P458.123[天文地球—大气科学及气象学]