Rourke, S. and Mulligan, F.J. and French, W.J.R. and Murphy, D.J. (2017) A Climatological Study of Short-Period Gravity Waves and Ripples at Davis Station, Antarctica (68°S, 78°E), During the (Austral Winter February–October) Period 1999–2013. Journal of Geophysical Research: Atmospheres, 122. ISSN 2169-8996

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Abstract

A scanning radiometer deployed at Davis Station, Antarctica (68°S, 78°E), has been recording infrared (1.10–1.65 μm) images of a small region (24 km × 24 km) of the zenith night sky once per minute each austral winter night since February 1999. These images have been processed to extract information on the passage of gravity waves (GWs) (horizontal wavelength, λh > 15 km) and ripples (λh ≤ 15 km) over the observing station. Phase speeds, periods, horizontal wavelengths, and predominant propagation directions have been deduced. Observed speeds were found to be highly correlated with horizontal wavelengths as has been reported in previous studies. Reverse ray tracing of the detected GWs only enabled us to identify four distinct groups. On average, only 15% of waves detected can be traced back to the troposphere, and a large proportion (~45%) were not successfully reverse traced substantially below the airglow layer. Two smaller groups were found to reach a termination condition for reverse ray tracing at altitudes near 50 km and 75 km. Of those that reached the termination altitude in the troposphere (10 km), most of the end points fell within a radius of 300 km of the station, with a very pronounced concentration of wave initiation to the northwest of the observing point. The predominant direction of propagation was southward, and they were observed throughout the year. Recent reports suggest the interaction of planetary waves with the background wind field as a potential source for these waves.

Item Type:	Article
Keywords:	gravity waves; mesopause; Antarctica;
Academic Unit:	Faculty of Science and Engineering > Experimental Physics
Item ID:	8950
Identification Number:	https://doi.org/10.1002/2017JD026998
Depositing User:	Sharon Rourke
Date Deposited:	03 Nov 2017 12:16
Journal or Publication Title:	Journal of Geophysical Research: Atmospheres
Publisher:	American Geophysical Union (AGU)
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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