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Quasi-10-day wave and semi-diurnal tide nonlinear interactions during the southern hemispheric SSW 2019 observed in the northern hemispheric mesosphere
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  • Maosheng He,
  • Jorge L. Chau,
  • Jeffrey M Forbes,
  • Denise Thorsen,
  • Guozhu Li,
  • Tarique A Siddiqui,
  • Yosuke Yamazaki,
  • Wayne K. Hocking
Maosheng He
Leibniz-Institute of Atmospheric Physics at the Rostock University

Corresponding Author:[email protected]

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Jorge L. Chau
Leibniz-Institute of Atmospheric Physics at the Rostock University
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Jeffrey M Forbes
University of Colorado Boulder
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Denise Thorsen
University of Alaska Fairbanks
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Guozhu Li
Institute of Geology and Geophysics, Chinese Academy of Sciences
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Tarique A Siddiqui
Leibniz-Institute of Atmospheric Physics at the Rostock University
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Yosuke Yamazaki
GFZ German Research Centre for Geosciences
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Wayne K. Hocking
University of Western Ontario
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Abstract

Mesospheric winds from three longitudinal sectors at about 65$^\circ$N and 54$^\circ$N latitude are combined to diagnose the zonal wavenumbers ($m$) of high-frequency-resolved spectral wave signatures during the rare southern hemisphere sudden stratospheric warming (SSW) of 2019. Diagnosed are quasi-10- and 6-day planetary waves (Q10DW and Q6DW, $m$=1), solar semi-diurnal tides with $m$=1, 2, 3 (SW1, SW2, and SW3), lunar semi-diurnal tide, and the upper and lower sidebands (USB and LSB, $m$=1 and 3) of Q10DW-SW2 nonlinear interaction. We further present a 7-year composite analysis to distinguish SSW effects from climatological behaviors. Immediately before (after) the SSW onset, LSB (USB) enhances, accompanied by the enhancing (fading) Q10DW, and a weakening of climatological SW2 maximum. These behaviors are explained in terms of Manley-Rowe energy relation, i.e., the energy goes first from SW2 to Q10DW and LSB, and then from SW2 and Q10DW to USB.
16 Dec 2020Published in Geophysical Research Letters volume 47 issue 23. 10.1029/2020GL091453