Simulations of large winds and wind shears induced by gravity wave breaking in the mesosphere and lower thermosphere (MLT) region

	Simulations of large winds and wind shears induced by gravity wave breaking in the mesosphere and lower thermosphere (MLT) region
	Liu, X.; Xu, J.; Liu, H. -L.; Yue, J.; Yuan, W.
刊名	ANNALES GEOPHYSICAE
	2014
卷号	32 期号:5 页码:543-552
关键词	Meteorology and atmospheric dynamics mesoscale meteorology middle atmosphere dynamics turbulence
ISSN号	0992-7689
通讯作者	Liu, X (reprint author), Chinese Acad Sci, Ctr Space Sci & Appl Res, State Key Lab Space Weather, Beijing 100190, Peoples R China.
英文摘要	Using a fully nonlinear two-dimensional (2-D) numerical model, we simulated gravity waves (GWs) breaking and their contributions to the formation of large winds and wind shears in the mesosphere and lower thermosphere (MLT). An eddy diffusion coefficient is used in the 2-D numerical model to parameterize realistic turbulent mixing. Our study shows that the momentum deposited by breaking GWs accelerates the mean wind. The resultant large background wind increases the GW's apparent horizontal phase velocity and decreases the GW's intrinsic frequency and vertical wavelength. Both the accelerated mean wind and the decreased GW vertical wavelength contribute to the enhancement of wind shears. This, in turn, creates a background condition that favors the occurrence of GW instability, breaking, and momentum deposition, as well as mean wind acceleration, which further enhances the wind shears. We find that GWs with longer vertical wavelengths and faster horizontal phase velocity can induce larger winds, but they may not necessarily induce larger wind shears. In addition, the background temperature can affect the time and height of GW breaking, thus causing accelerated mean winds and wind shears.
收录类别	SCI
语种	英语
内容类型	期刊论文
源URL	[http://ir.nssc.ac.cn/handle/122/4456]
专题	国家空间科学中心_空间科学部
推荐引用方式 GB/T 7714	Liu, X.,Xu, J.,Liu, H. -L.,et al. Simulations of large winds and wind shears induced by gravity wave breaking in the mesosphere and lower thermosphere (MLT) region[J]. ANNALES GEOPHYSICAE,2014,32(5):543-552.
APA	Liu, X.,Xu, J.,Liu, H. -L.,Yue, J.,&Yuan, W..(2014).Simulations of large winds and wind shears induced by gravity wave breaking in the mesosphere and lower thermosphere (MLT) region.ANNALES GEOPHYSICAE,32(5),543-552.
MLA	Liu, X.,et al."Simulations of large winds and wind shears induced by gravity wave breaking in the mesosphere and lower thermosphere (MLT) region".ANNALES GEOPHYSICAE 32.5(2014):543-552.