摘要
飓风“保莱特”(2020)在北大西洋经历了两次关键路径转折:从向北美大陆西北行转为东北行,随后完成温带变性;由东北行转为南行,继而再生为热带风暴。为了探究不同层次引导气流以及环流系统对飓风两次路径转折的影响,基于中尺度天气研究与预报(weather research and forecasting,WRF)模式对“保莱特”开展模拟研究。结果表明:1)“保莱特”再生与其异常南折路径密切相关,南移进入暖海温区是其重新发展的关键原因。2)“保莱特”移动过程中,引导气流呈现显著的垂直层次差异及变化。飓风西北行阶段中低层引导气流起主导作用;向东北转向及东北行阶段高层引导气流影响明显增强;向南转向阶段低层引导气流先由西风转为偏北风,随后自下而上逐步扩展至高层形成深厚的偏北气流,最终导致飓风路径异常南折。3)“保莱特”发展初期处于副热带高压南缘,受高压带阻挡而西北行。随着飓风增强,副热带高压断裂,“保莱特”北上移入中纬度西风槽中,并在槽前西南风引导作用下东北行。然而,“保莱特”南侧高压脊持续增强且经向度显著增大,最终导致飓风在高压脊前转向南行。
Hurricane Paulette(2020)underwent two critical track shifts over the North Atlantic:first,a turn from northwestward movement toward North America to northeastward movement,followed by extratropical transition;second,a shift from a northeastward track to a southward track,subsequently regenerating into a tropical storm.To investigate the influence of multi-level steering flows and surrounding circulation systems on these two turning processes,numerical simulations of Paulette were conducted using the Weather Research and Forecasting(WRF)model.The results show that:1)The regeneration of Paulette was closely associated with its anomalous southward turning,during which it moved into a region of warm sea surface temperature,acquiring favorable conditions for redevelopment.2)During the movement of Paulette,the steering flow exhibited significant vertical variation and evolution.The northwestward movement was primarily governed by low-to mid-level steering flows,while upper-level steering flows became more dominant during the northeastward turn and northeastward movement.During the southward-turning stage,lowlevel steering flows shifted from westerlies to northerlies,gradually extending upward to the upper levels and forming a deep northerly flow,ultimately leading to an abnormal southward turning of the hurricane's track.3)In its early developmental stage,Paulette was located to the southern periphery of the subtropical high and moved northwestward under its blocking influence.As the hurricane intensified,the subtropical high weakened and broke,allowing Paulette to move northward into a mid-latitude westerly trough and turn northeastward under the influence of southwesterly flow ahead of the trough.However,as the high-pressure ridge to the south of Paulette continued to strengthen with a significant increase in meridional extent,the hurricane ultimately turned southward ahead of the ridge.
作者
寿泽慧
刘俏
胡枫
王根
SHOU Zehui;LIU Qiao;HU Feng;WANG Gen(Anhui Meteorological Observatory,Hefei 230031,China;Anhui Province Key Laboratory of Physical Geographic Environment,Anhui Engineering Research Center of Remote Sensing and Geoinformatics,Chuzhou University,Chuzhou 239000,China;Key Laboratory of Meteorological Disaster(KLME),Ministry of Education&Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD),Nanjing University of Information Science&Technology,Nanjing 210044,China;School of Electronic Engineering,Chaohu University,Hefei 238000,China)
出处
《热带海洋学报》
北大核心
2026年第2期71-80,共10页
Journal of Tropical Oceanography
基金
安徽省自然科学基金项目(2308085QD129、2408085MD102)
实景地理环境安徽省重点实验室开放课题项目(2023PGE05)
安徽省高校杰出青年科学基金项目(2022AH020093)。
关键词
飓风“保莱特”
引导气流
环境背景场
Hurricane Paulette
steering flow
environmental background field
