Tidal analysis of meridional winds at the South Pole using a VHF interferometric meteor radar

Autor: Scott Palo, E. M. Lau, J. P. Avery, N. A. Makarov, Susan K. Avery
Rok vydání: 2006
Předmět:
Zdroj: Journal of Geophysical Research. 111
ISSN: 0148-0227
DOI: 10.1029/2005jd006734
Popis: [1] Atmospheric tides are perturbations driven by the periodic absorption of solar radiation. They manifest themselves everywhere in the atmosphere, and an understanding of their sources, propagation, and interaction with other waves is vital to comprehend the global atmosphere. In order to measure the horizontal wind field in the mesosphere–lower thermosphere (MLT) over the geographical South Pole and use these measurements to understand the large-scale dynamics of this region, a VHF meteor radar was installed at the Amundsen-Scott station at the South Pole in 2001. The radar operated for a few months in 2001 and with minor interruptions in 2002 and 2003. However, toward the end of 2003, receiver problems caused a drop in our meteor echo rates, preventing us from getting tidal results after October 2003. We report on the temporal behavior of the diurnal and semidiurnal tides observed in the meridional wind field at mesospheric and lower thermospheric heights in the vicinity of the geographic South Pole. With the interferometric capabilities of this radar, we also document for the first time the vertical structure of these tides. The zonal wave number one component of the diurnal tide shows consistency for all years that we analyze. On the other hand, the zonal wave number one component of the semidiurnal tide shows significantly more year-to-year variability. Our results are compared to previous observations and model predictions. A significant decrease in the amplitude of this oscillation from December 2002 to February 2003 is also observed and discussed.
Databáze: OpenAIRE
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