Japan Geoscience Union Meeting 2025

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A (Atmospheric and Hydrospheric Sciences ) » A-AS Atmospheric Sciences, Meteorology & Atmospheric Environment

[A-AS06] Atmospheric (Stratosphere-troposphere) Processes And their Role in Climate

Tue. May 27, 2025 5:15 PM - 7:15 PM Poster Hall (Exhibition Hall 7&8, Makuhari Messe)

convener:Shunsuke Noguchi(Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University), Yayoi Harada(Meteorological Research Institute), Kazuaki Nishii(Graduate School of Bioresources, Mie University), Nawo Eguchi(Research Institute for Applied Mechanics, Kyushu University)



5:15 PM - 7:15 PM

[AAS06-P06] Two leading modes in the evolution of major sudden stratospheric warmings and their distinctive surface influence

*Lei Song1 (1.Institute of Atmospheric Physics, Chinese Academy of Sciences)

Keywords:Sudden stratospheric warming, polar vortex, planetary waves, surface influence

Height-time domain empirical orthogonal function (EOF) analysis is conducted to extract the dominant variations in the evolution of stratospheric sudden warming events (SSWs). The EOF1 corresponds to weak (I+) and strong (I-) polar vortex before the onset of SSWs and EOF2 indicates strong (W+) and weak (W-) warming during SSWs. The development of I- SSWs is associated with stronger eddy heat flux contributed by planetary wavenumbers 1 and 2, whereas the I+ SSWs is related to wavenumber 1. W+ SSWs are linked to both wavenumbers 1 and 2,while the happening of W- SSWs is associated with wavenumber 1. SSWs of I+ and W+ can exert influence on the surface such as negative phase of the North Atlantic Oscillation, which indicates that SSWs with different initial polar vortex states and warming intensities lead to different surface influence. This could help to better predict the tropospheric response following SSWs.