高空冷涡对台风烟花(2106)路径的影响  

Impacts of Upper Tropospheric Cold Low on the Track of Typhoon In-fa in 2021

作　　者：王海平 Wang Haiping(National Meteorological Center,Beijing 100081)

机构地区：[1]国家气象中心,北京100081

出　　处：《应用气象学报》2023年第5期586-597,共12页Journal of Applied Meteorological Science

基　　金：国家重点研发计划(2021YFB3900405);国家气象中心预报员专项(Y202109)。

摘　　要：2021年台风烟花(2106)移动路径复杂,经历多次移动方向和速度的异常变化,数值模式及主观综合预报对其路径预报均误差较大,模式对120 h预报误差最大达到400~800 km。通过研究导致模式对初次登陆时间及位置预报出现明显偏差的原因发现,高空冷涡的存在有利于副热带高压东退,使得影响台风烟花的引导气流减弱,移速明显减慢,24 h平均移动速度仅为3.6 km·h^(-1)。随着副热带高压的继续北抬减弱,高空冷涡减弱后的西风槽前偏南气流引导是台风烟花移动路径出现明显偏北分量、登陆浙北地区的重要原因。通过对确定性预报和集合预报分析发现,数值模式对高空冷涡的预报仍存在较大误差和不确定性,是导致台风烟花路径预报误差较大的主要原因。Typhoon In-fa lands on the coast of Zhoushan,Zhejiang Province on 25 July 2021,bringing severe wind and rain to the coastal areas for a long time.Before landing,it maintains in the sea,east of Ryukyu Islands and then suddenly turns northward.The official subjective and numerical model forecasts both produce serious errors on the landing time and location,which has a certain impact on the decision of disaster prevention.Using the best track data of China Meteorological Administration(CMA)and the water vapor channel data of FY-4A satellite cloud image,the characteristics of Typhoon In-fa,especially the causes of its stagnation and northerly bend are investigated.Deterministic model forecast results from the regional mesoscale typhoon numerical forecast system(CMA-TYM),the fine-grid numerical forecast product of European Center for Medium-range Weather Forecasts(ECMWF)and National Center for Environmental Prediction Center(NCEP),and ECMWF ensemble forecast data are also analyzed.The fifth generation global climate reanalysis data set ERA5 is used for the analysis of the real situation field and physical quantity field.The center of the upper-tropospheric cold low(UTCL)is determined by referring to the water vapor channel of the satellite cloud image and the horizontal flow field is obtained according to the wind field data of ERA5.The center of the cyclonic circulation over 200 hPa is set as the center of UTCL.Through FY-4A water vapor cloud image,it is found that in the stagnation stage of Typhoon In-fa,there is a UTCL system on the north side.By analyzing the vertical distribution of circulation situation field,steering flow,and relative vorticity,it is found that the position of the subtropical high system is to the east and north,and typhoon guiding effect on the typhoon is weak.Therefore,the main weather systems that affect the change of its track are the UTCL and westerly trough system in the upper troposphere.There are also differences in the interaction between UTCL and typhoon at different intensities and d

关 键 词：台风烟花(2106) 北折路径 高空冷涡 模式误差 

分 类 号：P444[天文地球—大气科学及气象学]