Statistics on Nonmigrating Diurnal Tides Generated by Tide-Planetary Wave Interaction and Their Relationship to Sudden Stratospheric Warming

Atmosphere

Xuwen Zhu¹  Jian Du²  Xiaojuan Niu³ 

[1] Department of Mathematics, University of Louisville, Louisville, KY 40292, USA;Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292, USA;Department of Physics, Jianghan University, Wuhan 430000, China;

关键词: nonlinear interaction;    sudden stratospheric warming;    planetary waves;    atmospheric tides;   

DOI  :  10.3390/atmos9110416

来源: DOAJ

【 摘 要 】

The nonmigrating diurnal tide, DW2, is known to have a source from the stationary planetary wave with wavenumber 1 (SPW1) and the migrating diurnal tide (DW1) interaction. Recent research has shown that DW2 time evolution in the equatorial mesopause tracks very well with SPW1 in the polar stratosphere for the winter of 2009⁻2010, which contains a sudden stratospheric warming (SSW) vortex split event. This paper extends previous research and investigates the relationship between these two waves for 31 winters from 1979 to 2010 with the extended Canadian Middle Atmosphere Model (eCMAM) through correlation and composite analysis. Significant correlations are present between the two waves in 20 out of 31 winters (65%). We separate the 31 winters into four categories: SSW-displacement, SSW-split, minor-SSW, and no-SSW. Our results show that there is no significant difference among the four categories in terms of correlations between the two waves. Although SPW1 is usually stronger during a SSW-D winter, this does not warrant a stronger interaction with DW2.

【 授权许可】

Unknown