气候变化领域集成服务门户(CCPortal): Lidar Observations of Instability and Estimates of Vertical Eddy Diffusivity Induced by Gravity Wave Breaking in the Arctic Mesosphere

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DOI	10.1029/2020JD033450
	Lidar Observations of Instability and Estimates of Vertical Eddy Diffusivity Induced by Gravity Wave Breaking in the Arctic Mesosphere
	Li J.; Collins R.; Lu X.; Williams B.
发表日期	2021
ISSN	2169897X
卷号	126 期号:4
英文摘要	On the night of 18–19 October 2018, sodium resonance lidar measurements show the presence of overturning in the mesospheric sodium layer. Two independent tracers, sodium mixing ratio and potential temperature, derived from resonance and Rayleigh lidar measurements, reveal that vertical spreading of the sodium mixing ratio contours and a layer of convective instability coincide with this overturning. Analysis of lidar measurements also reveals the presence of gravity waves that propagate upward, are saturated, and dissipate at the height of the convective instability. The vertical spreading is analyzed in terms of turbulent diffusive transport using a model based on material continuity of sodium. Estimates of the turbulent eddy diffusion coefficient, K, and energy dissipation rate, ε are derived from the transport model. The energy dissipated by the gravity waves is also calculated and found to be sufficient to generate the turbulence. We consider three other examples of overturning, instability and spreading on the nights of: 17–18 February 2009, 25–26 January 2015, and 8–9 October 2018. For all four events we find that the values of K (∼1,000 m2/s) are larger and the values of ε (∼10–100 mW/kg) are of similar magnitude to those values typically reported by ionization gauge measurements. These examples also reveal that higher levels of turbulent mixing are consistently found in regions of lower stability. © 2020. The Authors.
英文关键词	diffusion; gravity wave; instability; lidar; turbulence
语种	英语
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/185320
作者单位	Department of Physics and Astronomy, Clemson University, Clemson, SC, United States; Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, United States; GATS, Boulder, CO, United States
推荐引用方式 GB/T 7714	Li J.,Collins R.,Lu X.,et al. Lidar Observations of Instability and Estimates of Vertical Eddy Diffusivity Induced by Gravity Wave Breaking in the Arctic Mesosphere[J],2021,126(4).
APA	Li J.,Collins R.,Lu X.,&Williams B..(2021).Lidar Observations of Instability and Estimates of Vertical Eddy Diffusivity Induced by Gravity Wave Breaking in the Arctic Mesosphere.Journal of Geophysical Research: Atmospheres,126(4).
MLA	Li J.,et al."Lidar Observations of Instability and Estimates of Vertical Eddy Diffusivity Induced by Gravity Wave Breaking in the Arctic Mesosphere".Journal of Geophysical Research: Atmospheres 126.4(2021).