气候变化领域集成服务门户(CCPortal): Mechanism Studies of Madden-Julian Oscillation Coupling Into the Mesosphere/Lower Thermosphere Tides Using SABER, MERRA-2, and SD-WACCMX

CCPortal

DOI	10.1029/2021JD034595
	Mechanism Studies of Madden-Julian Oscillation Coupling Into the Mesosphere/Lower Thermosphere Tides Using SABER, MERRA-2, and SD-WACCMX
	Kumari K.; Wu H.; Long A.; Lu X.; Oberheide J.
发表日期	2021
ISSN	2169-897X
卷号	126 期号:13
英文摘要	The Madden-Julian Oscillation (MJO), an eastward-moving disturbance near the equator (±30°) that typically recurs every ∼30–90 days in tropical winds and clouds, is the dominant mode of intraseasonal variability in tropical convection and circulation and has been extensively studied due to its importance for medium-range weather forecasting. A previous statistical diagnostic of SABER/TIMED observations and the MJO index showed that the migrating diurnal (DW1) and the important nonmigrating diurnal (DE3) tide modulates on MJO-timescale in the mesosphere/lower thermosphere (MLT) by about 20%–30%, depending on the MJO phase. In this study, we address the physics of the underlying coupling mechanisms using SABER, MERRA-2 reanalysis, and SD-WACCMX. Our emphasis was on the 2008–2010 time period when several strong MJO events occurred. SD-WACCMX and SABER tides show characteristically similar MJO-signal in the MLT region. The tides largely respond to the MJO in the tropospheric tidal forcing and less so to the MJO in tropospheric/stratospheric background winds. We further quantify the MJO response in the MLT region in the SD-WACCMX zonal and meridional momentum forcing by separating the relative contributions of classical (Coriolis force and pressure gradient) and nonclassical forcing (advection and gravity wave drag [GWD]) which transport the MJO-signal into the upper atmosphere. Interestingly, the tidal MJO-response is larger in summer due to larger momentum forcing in the MLT region despite the MJO being most active in winter. We find that tidal advection and GWD forcing in MLT can work together or against each other depending on their phase relationship to the MJO-phases. © 2021. The Authors.
英文关键词	atmospheric tides; intraseasonal; Madden-Julian oscillation; MERRA2; SABER; SDWACCMX
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/237142
作者单位	Department of Physics and Astronomy, Clemson University, Clemson, SC, United States
推荐引用方式 GB/T 7714	Kumari K.,Wu H.,Long A.,et al. Mechanism Studies of Madden-Julian Oscillation Coupling Into the Mesosphere/Lower Thermosphere Tides Using SABER, MERRA-2, and SD-WACCMX[J],2021,126(13).
APA	Kumari K.,Wu H.,Long A.,Lu X.,&Oberheide J..(2021).Mechanism Studies of Madden-Julian Oscillation Coupling Into the Mesosphere/Lower Thermosphere Tides Using SABER, MERRA-2, and SD-WACCMX.Journal of Geophysical Research: Atmospheres,126(13).
MLA	Kumari K.,et al."Mechanism Studies of Madden-Julian Oscillation Coupling Into the Mesosphere/Lower Thermosphere Tides Using SABER, MERRA-2, and SD-WACCMX".Journal of Geophysical Research: Atmospheres 126.13(2021).