Southwestward propagation mechanism of the 10-30-day oscillation along the eastern coast of East Asia in summerOA
Southwestward propagation mechanism of the 10-30-day oscillation along the eastern coast of East Asia in summer
中高纬度大气季节内振荡(ISO)在全球尺度上主要表现为纬向传播特征,而在欧亚中高纬度地区则存在东南和西南传的10-30天ISO模态.现有研究已揭示东南传ISO机制,但西南向传播的动力过程尚不明确.本项目基于ERA5再分析数据,通过涡度收支诊断,系统研究了沿东亚东岸西南向传播的10-30天ISO特征及动力机制.结果表明,夏季东亚10-30天ISO的西南传播模态主要表现为东北亚向长江中游的传播途径.涡度收支分析明确了相对涡度平流是驱动系统西南移动的关键因子,而地转涡度平流则抑制其传播速率,这一现象显著区别于传统认知的西风带涡度平流作用.机制分析进一步表明,10-30天扰动位势高度异常的东北-西南向倾斜非对称结构与西风背景场间存在显著的尺度间相互作用,其中背景风对扰动气旋的纬向平流主导了系统的西南传播.本研究阐明了中高纬度ISO在倾斜结构下的独特传播机制,厘清了相对涡度平流与地转涡度平流的协同作用,为东亚夏季季节内变率的预测提供了新的理论依据.
Yue Wang;Suxiang Yao
State Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster,Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology,Nanjing,ChinaState Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster,Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology,Nanjing,China
季节内振荡西南向传播相对涡度平流涡度收支
Intraseasonal oscillationSouthwestward propagationRelative vorticity advectionVorticity budget
《大气和海洋科学快报（英文版）》 2026 (4)
40-46,7
This work was sponsored by the National Key R&D Program of China[grant numbers 2023YFF0805701 and 2024YFC3013100].
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