Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
doi:10.5194/acp-2016-813
© Author(s) 2016. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
14 Nov 2016
Review status
A revision of this discussion paper was accepted for the journal Atmospheric Chemistry and Physics (ACP) and is expected to appear here in due course.
Quasi 12 h inertia-gravity waves in the lower mesosphere observed by the PANSY radar at Syowa Station (39.6 °E, 69.0 °S)
Ryosuke Shibuya1, Kaoru Sato1, Masaki Tsutsumi2,3, Toru Sato4, Yoshihiro Tomikawa2,3, Koji Nishimura2,3, and Masashi Kohma1 1Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan
2National Institute of Polar Research, Tachikawa, Japan
3The Graduate University for Advanced Studies (SOKENDAI), Tokyo, Japan
4Department of Communications and Computer Engineering, Kyoto University, Japan
Abstract. The first observations made by a complete PANSY radar system (Program of the Antarctic Syowa MST/IS Radar) installed at Syowa Station (39.6 °E, 69.0 °S) were successfully performed from March 16–24, 2015. Over this period, quasi-half-day period (12 h) disturbances in the lower mesosphere at heights of 70 km to 80 km were observed. Estimated vertical wavelengths, wave periods and vertical phase velocities of the disturbances were approximately 13.7 km, 12.3 h and −0.3 m s−1, respectively. Under the working hypothesis that such disturbances are attributable to inertia-gravity waves, wave parameters are estimated using a hodograph analysis. The estimated horizontal wavelengths are longer than 1100 km, and the wavenumber vectors tend to point northeastward or southwestward. Using the non-hydrostatic numerical model with a model top of 87 km, quasi 12 h disturbances in the mesosphere were successfully simulated. We show that quasi 12 h disturbances are due to wave-like disturbances with horizontal wavelengths longer than 1400 km and are not due to semi-diurnal migrating tides. Wave parameters, such as horizontal wavelengths, vertical wavelengths and wave periods, simulated by the model agree well with those estimated by the PANSY radar observations under the above-mentioned assumption. The parameters of the simulated waves are consistent with the dispersion relationship of the inertia-gravity wave. These results indicate that the quasi 12 h disturbances observed by the PANSY radar are attributable to large-scale inertia-gravity waves. By examining a residual of the nonlinear balance equation, it is inferred that the inertia-gravity waves are likely generated by the spontaneous radiation mechanism of two different jet streams. One is the mid-latitude tropospheric jet around the tropopause while the other is the polar night jet. Large vertical fluxes of zonal and meridional momentum associated with large-scale inertia-gravity waves are distributed across a slanted region from the mid-latitude lower stratosphere to the polar mesosphere in the meridional cross-section. Moreover, the vertical flux of the zonal momentum has a strong negative peak in the mesosphere, suggesting that some large-scale inertia-gravity waves originate in the upper stratosphere.

Citation: Shibuya, R., Sato, K., Tsutsumi, M., Sato, T., Tomikawa, Y., Nishimura, K., and Kohma, M.: Quasi 12 h inertia-gravity waves in the lower mesosphere observed by the PANSY radar at Syowa Station (39.6 °E, 69.0 °S), Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-813, in review, 2016.
Ryosuke Shibuya et al.
Ryosuke Shibuya et al.

Viewed

Total article views: 341 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
266 49 26 341 14 26

Views and downloads (calculated since 14 Nov 2016)

Cumulative views and downloads (calculated since 14 Nov 2016)

Viewed (geographical distribution)

Total article views: 341 (including HTML, PDF, and XML)

Thereof 339 with geography defined and 2 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 26 May 2017
Publications Copernicus
Download
Short summary
The first observations made by a complete PANSY radar system (Program of the Antarctic Syowa MST/IS Radar) installed at Syowa Station were successfully performed from March 16–24, 2015. Over this period, quasi 12 h period disturbances in the mesosphere at heights of 70 km to 80 km were observed. Combining the observational data and numerical simulation outputs, we found that quasi 12 h disturbances are due to large-scale inertia-gravity waves, not due to semi-diurnal migrating tides.
The first observations made by a complete PANSY radar system (Program of the Antarctic Syowa...
Share