摘要
使用中国气象局热带气旋最佳路径数据集和美国国家环境预报中心再分析资料,分析了2018年3个登陆北上台风的长期维持环境背景及热力和动力条件。结果表明:在较低纬度时,垂直风切变≤10m/s,副热带高压呈块状分布,其西脊点一般不超过120°E,且西风槽位置整体偏北,台风主要受副热带高压外围偏南引导气流影响,路径大多在平原,摩擦耗散较小,配合南亚高压东侧反气旋环流第三象限辐散和低空强度相当的辐合条件以及西南和东南暖湿输送影响,台风中心附近平均涡度减弱缓慢;当北上受高空急流影响的垂直风切变增大时,低空出现明显湿能量辐合,有明显积云对流发展和高层凝结潜热释放,且受高空急流入口区影响,高空辐散也增强,利于台风登陆后期的维持。
Based on the tropical cyclone best track datasets of the China Meteorological Administration and reanalysis data of the National Centers for Environmental Prediction,the environmental thermodynamic-dynamic conditions for the long-term maintenance of three northward-moving typhoons after landing in 2018 are analyzed.It is found that,when the typhoon is at lower latitudes,the vertical wind shear is less than 10 m/s,the subtropical high is in a block shape.The west ridge point of the subtropical high generally locates east of 120°E,and the westerly trough locates north than normal position.The typhoon is mainly influenced by the southerly air flow in the periphery of the subtropical high,and its path mainly locates in the plain,so the friction dissipation is small.Combined with the divergence in the third quadrant of the anticyclone circulation east of the South Asian High and the convergence with similar strength in low-level atmosphere,as well as the southwest and southeast warm and humid supplementation,the mean vorticity near the typhoon center weakens slowly.When the typhoon is northward-moving,the vertical wind shear slightly increases affected by the high-level jet,wet energy convergence appears at the low-level atmosphere.With developing of cumulus convective and latent heat releasing in the high-level atmosphere,the divergence also increases in inlet area of the high-level jet,which benefits for the maintenance of typhoon in the later stage of landfall.
作者
王亚男
苏杭
易笑园
WANG Yanan;SU Hang;YI Xiaoyuan(Tianjin Marine Meteorological Centre,Tianjin 300074,China;Tianjin Key Laboratory for Oceanic Meteorology,Tianjin 300074,China;Tianjin Meteorological Observatory,Tianjin 300074,China)
出处
《海洋预报》
CSCD
北大核心
2023年第4期97-106,共10页
Marine Forecasts
基金
中国气象局预报员专项项目(CMAYBY2019-008)
国家重点研发计划重点专项(2019YFC1510100)。
关键词
台风
登陆北上
长期维持
环境背景
热力动力诊断
合成分析
typhoon
landing and northward-movement
long-term maintenance
environmental background
thermal and dynamic diagnosis
synthetic analysis
