Abstract
Abstract
The steering flow of the large-scale circulation patterns over the western North Pacific and North East Asia, constrains typhoon tracks. Westerly winds impinging on the Tibetan Plateau, and the resulting flow uplift along the slope of the mountain, induce atmospheric vortex flow and generate stationary barotropic Rossby waves downstream. The downstream Rossby wave zonal phase is determined by the upstream zonal wind speed impinging on the Tibetan Plateau. Negative anomaly of westerly wind forcing tends to induce a westward shift of the large-scale Rossby wave circulation pattern, forming an anti-cyclonic circulation anomaly over North East Asia. In this study, we show that the Tibetan Plateau dynamically impacts the tracks of western Pacific typhoons via modulation of downstream Rossby waves. Using the topographically forced stationary Rossby wave theory, the dynamical mechanisms for the formation of the North East Asian anti-cyclonic anomaly and its impact on the typhoon tracks are analyzed. The westward shift of typhoon tracks caused by the southeasterly wind anomaly, or track density increase over the western flank of the North East Asian anti-cyclonic circulation anomaly is robust in June, August and September, but it is not statistically significant in July. The physical understanding of the large-scale circulation pattern affecting typhoon trajectories has large implications not only at the seasonal prediction of the high impact weather phenomena, but also at the right understanding of the long-term climate change.
Funder
Ministry of Oceans and Fisheries
Subject
Public Health, Environmental and Occupational Health,General Environmental Science,Renewable Energy, Sustainability and the Environment
Cited by
10 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献