This study presents an analysis of OH airglow images observed from an all-sky camera (ASC) at King Sejong Station (KSS), Antarctic for the 2012–2016 period. The two-dimensional power spectra of short-period gravity waves (<1 hr) as a function of phase velocities are obtained using the M-transform method that employs the time sequence of ASC images. The amplitudes of the power spectral densities show that the mesospheric wave activity is the largest during winter (May, June, and July) and is the smallest in fall (February, March, and April). Wind-blocking diagrams are constructed on the same two-dimensional domain as in the two-dimensional spectra using horizontal winds obtained from MERRA-2 reanalysis at z = 0–80 km and from KSS meteor radar data at z = 80–90 km. Climatologically, the spectral regions of slowly propagating gravity waves (<30 m s−1) are overlaid by the wind-blocking areas, which suggests the filtering of gravity waves with small phase speeds by winds below the upper stratosphere. Eastward propagating gravity waves in winter and intense south-eastward waves in spring (October) are found to be unfiltered by the stratospheric winds. It is also found from the spectral analysis that these unfiltered gravity waves can originate from the upper stratosphere or the lower mesosphere, and not from the troposphere, which suggests the possibility of ASC observation of the secondary gravity waves generated near the stratopause.
|Journal||Journal of Geophysical Research: Atmospheres|
|Publication status||Published - 2021 Dec 27|
Bibliographical noteFunding Information:
This research was supported by basic research funding from the Korea Astronomy and Space Science Institute (KASI) (KASI2021185005)and by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (2019K2A9A1A0610292012). This work was also supported by grant PE21020 from the Korea Polar Research Institute and studied as a part of collaboration work in the ANGWIN community. M. K. was supported by the JSPS grant JRPs‐LEAD with DFG program, JSPS KAKENHI 19K23465 and the Scientific Committee on Antarctic Research (SCAR) fellowship award 2019.
© 2021. The Authors.
All Science Journal Classification (ASJC) codes
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science