Location of Repository

Observation of a mesospheric front in a thermal-doppler duct over King George Island, Antarctica

By J. V. Bageston, C. M. Wrasse, P. P. Batista, R. E. Hibbins, D. C Fritts, D. Gobbi and V. F. Andrioli

Abstract

A mesospheric front was observed with an all-sky airglow imager on the night of 9–10 July 2007 at Ferraz Station (62° S, 58° W), located on King George island on the Antarctic Peninsula. The observed wave propagated from southwest to northeast with a well defined wave front and a series of crests behind the main front. The wave parameters were obtained via a 2-D Fourier transform of the imager data providing a horizontal wavelength of 33 km, an observed period of 6 min, and a horizontal phase speed of 92 m s<sup>−1</sup>. Simultaneous mesospheric winds were measured with a medium frequency (MF) radar at Rothera Station (68° S, 68° W) and temperature profiles were obtained from the SABER instrument on the TIMED satellite. These wind and temperature profiles were used to estimate the propagation environment of the wave event. A wavelet technique was applied to the wind in the plane of wave propagation at the OH emission height spanning three days centered on the front event to define the dominant periodicities. Results revealed a dominance of near-inertial periods, and semi-diurnal and terdiurnal tides suggesting that the ducting structure enabling mesospheric front propagation occurred on large spatial scales. The observed tidal motions were used to reconstruct the winds employing a least-squares method, which were then compared to the observed ducting environment. Results suggest an important contribution of large-scale winds to the ducting structure, but with buoyancy frequency variations in the vertical also expected to be important. These results allow us to conclude that the wave front event was supported by a duct including contributions from both winds and temperature

Topics: Environmental sciences, GE1-350, Geography. Anthropology. Recreation, G, DOAJ:Environmental Sciences, DOAJ:Earth and Environmental Sciences, Physics, QC1-999, Chemistry, QD1-999
Publisher: Copernicus Publications
Year: 2011
DOI identifier: 10.5194/acp-11-12137-2011
OAI identifier: oai:doaj.org/article:2cf4cbf842b745628181d739fbdc443a
Journal:
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • https://doaj.org/toc/1680-7324 (external link)
  • https://doaj.org/toc/1680-7316 (external link)
  • http://www.atmos-chem-phys.net... (external link)
  • https://doaj.org/article/2cf4c... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.