High- to Low-Frequency Gravity Waves Observed in Vertical Winds and Temperatures over McMurdo, Antarctica
Abstract
Eight years of Fe Boltzmann lidar observations at Arrival Heights Observatory near McMurdo have discovered persistent gravity waves with periods of 3-10 h and vertical wavelengths of 20-30 km in the mesosphere and lower thermosphere (MLT), and characterized dominant gravity waves and potential energy densities in the stratosphere. Secondary gravity wave generation theorized by Vadas et al. (2018) and high-resolution general circulation model (Becker and Vadas, 2018) stitch together the dissipation of orographic gravity waves, the lidar-observed fishbone structures in the stratospheric temperatures, and the persistent gravity waves in the MLT. In addition, the wintertime Fe lidar data enable the profiling of gravity waves with periods of 1.5 h from the stratosphere all the way to the thermosphere as shown in the thermosphere-ionosphere Fe (TIFe) layers. A new Na Doppler lidar installed in the same laboratory as the Fe lidar is delivering high-resolution measurements of vertical winds and temperatures in the MLT region. The vertical wind data clearly reveal high-frequency waves with periods of 10 min, in addition to the gravity waves with 1.5 h and inertial periods, and these high- to low-frequency wave signatures also show up in the high-resolution temperature data from the Na lidar. We will characterize the high- to low-frequency gravity waves from the aspects of polarization relation, frequency spectra, and vertical wavenumber spectra. In combination with the multiple years of Fe lidar observations, we hope to establish a big picture of gravity waves from the surface to the thermosphere.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMSA43A..04C
- Keywords:
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- 3369 Thermospheric dynamics;
- ATMOSPHERIC PROCESSESDE: 3384 Acoustic-gravity waves;
- ATMOSPHERIC PROCESSESDE: 3389 Tides and planetary waves;
- ATMOSPHERIC PROCESSESDE: 2427 Ionosphere/atmosphere interactions;
- IONOSPHERE