DOI: 10.1002/2017JD027303
Scopus记录号: 2-s2.0-85040687698
论文题名: Observations of the Breakdown of Mountain Waves Over the Andes Lidar Observatory at Cerro Pachon on 8/9 July 2012
作者: Hecht J.H. ; Fritts D.C. ; Wang L. ; Gelinas L.J. ; Rudy R.J. ; Walterscheid R.L. ; Taylor M.J. ; Pautet P.D. ; Smith S. ; Franke S.J.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 1 起始页码: 276
结束页码: 299
语种: 英语
英文关键词: gravity waves
; turbulence
Scopus关键词: airglow
; gravity wave
; Kelvin-Helmholtz instability
; observational method
; orographic effect
; stratosphere
; turbulence
; viscosity
; vortex
; wave breaking
; winter
; Andes
英文摘要: Although mountain waves (MWs) are thought to be a ubiquitous feature of the wintertime southern Andes stratosphere, it was not known whether these waves propagated up to the mesopause region until Smith et al. (2009) confirmed their presence via airglow observations. The new Andes Lidar Observatory at Cerro Pachon in Chile provided the opportunity for a further study of these waves. Since MWs have near-zero phase speed, and zero wind lines often occur in the winter upper mesosphere (80 to 100 km altitude) region due to the reversal of the zonal mean and tidal wind, MW breakdown may routinely occur at these altitudes. Here we report on very high spatial/temporal resolution observations of the initiation of MW breakdown in the mesopause region. Because the waves are nearly stationary, the breakdown process was observed over several hours; a much longer interval than has previously been observed for any gravity wave breakdown. During the breakdown process observations were made of initial horseshoe-shaped vortices, leading to successive vortex rings, as is also commonly seen in Direct Numerical Simulations (DNS) of idealized and multiscale gravity wave breaking. Kelvin-Helmholtz instability (KHI) structures were also observed to form. Comparing the structure of observed KHI with the results of existing DNS allowed an estimate of the turbulent kinematic viscosity. This viscosity was found to be around 25 m2/s, a value larger than the nominal viscosity that is used in models. ©2017. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114696
Appears in Collections: 气候减缓与适应
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作者单位: Space Science Applications Laboratory, Aerospace Corporation, El Segundo, CA, United States; GATS Inc., Boulder, CO, United States; Center for Atmospheric and Space Sciences, Utah State University, Logan, UT, United States; Center for Space Physics, Boston University, Boston, MA, United States; Electrical and Computer Engineering, University of Illinois, Urbana, IL, United States
Recommended Citation:
Hecht J.H.,Fritts D.C.,Wang L.,et al. Observations of the Breakdown of Mountain Waves Over the Andes Lidar Observatory at Cerro Pachon on 8/9 July 2012[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(1)