大气科学学报2025，Vol.48Issue(4)：576-591,16.DOI:10.13878/j.cnki.dqkxxb.20240903003
平流层温度异常对夏季北极气旋发展与维持的影响分析
Analysis of the impact of stratospheric temperature anomalies on the de-velopment and maintenance of summer Arctic cyclones
摘要
Abstract
In recent decades,with global warming,the Arctic region has exhibited a particularly significant war-ming trend.As a critical component of the high-latitude climate system,Arctic cyclones are closely linked to vari-ous weather phenomena in the Arctic,such as extreme winds and heavy precipitation events.Different from extrat-ropical cyclones in midlatitude,the development and maintenance of some Arctic cyclones are influenced by the tropopause polar vortex(TPV).And the strengthening,maintenance,and vertical structure of these cyclones show significant differences due to effects of the TPV.The climate system in the Arctic region is complex and diverse.Therefore,to further explore the influence mechanism of Arctic cyclones while considering their unique physical mechanism,we aim to study the impact of stratospheric temperature anomalies on the development and mainte-nance of Arctic cyclones in summer. At three characteristic phases of cyclone lifecycle-initial formation,peak intensity,and maximum intensifica-tion rate-the distances between cyclone centers and TPV centers were systematically calculated.If the distance is less than 1000 km,it is considered that there is a connection between the cyclone and TPV,and it is a TPV cy-clone.Conversely,it is determined to be a cyclone unrelated to TPV,that is,a non-TPV cyclone.Two representa-tive intense cyclone cases were selected from the top 100 cyclones in the northern marginal of Eurasia region(NMER):one exhibiting strong dynamical coupling with the TPV and the other unrelated to TPV.Through the weather research and forecasting(WRF)numerical model,control and sensitivity experiments were designed and executed to conduct a comparative investigation into how stratospheric temperature anomalies modulate cyclones of contrasting structural types and their regionally correlated precipitation responses. The analysis reveals that cyclone cases closely associated with the TPV are influenced by the downward in-trusion of high potential vorticity from the stratosphere into the troposphere,exhibiting a distinct quasi-barotropic structure with a warm-over-cold pattern.In the sensitivity experiments,after reducing the horizontal thermal differ-ences in the upper troposphere and above,the folding characteristics of the tropopause are significantly weakened.Correspondingly,the stratospheric potential vorticity intrusion and absolute vorticity around the cyclone center are notably reduced,leading to a significant decrease in both the intensity of the cyclone center and the associated precipitation.In contrast,for another Arctic cyclone process unrelated to TPV activity,the formation and develop-ment are primarily driven by baroclinic instability.The horizontal thermal differences in the stratosphere would not show significant changes in the cyclone intensity or precipitation.The study primarily investigates the impacts of stratospheric temperature anomalies on Arctic cyclones,while there are relatively few discussions on other impor-tant factors that may affect Arctic cyclone activities and precipitation,such as ocean circulation,the feedback mechanism of the interaction between sea ice changes and the atmosphere.Future research requires expansion of cyclone case samples to enable more comprehensive investigations.Meanwhile,in order to refine the impact on precipitation more precisely,in the subsequent further study of the precipitation accompanying different types of Arctic cyclones,a higher resolution can be selected for WRF simulation to compare and analyze the possible pre-cipitation differences caused by the resolution.关键词
北极气旋/平流层温度异常/位涡/斜压不稳定/北极降水Key words
Arctic cyclone/stratospheric temperature anomaly/potential vorticity/baroclinic instability/Arctic precipitation引用本文复制引用
白亚雯,卢楚翰,粟云鹏,孔阳,陶玮,丁留贯..平流层温度异常对夏季北极气旋发展与维持的影响分析[J].大气科学学报,2025,48(4):576-591,16.基金项目
江苏省重点研发计划产业前瞻与关键核心技术项目(BE2022161) （BE2022161）
无锡市"太湖之光"科技攻关(基础研究)项目(K20231023) （基础研究）
江苏省高校"青蓝工程"资助项目 （）
无锡学院引进人才科研启动专项(2023r037) （2023r037）
