Intradiurnal wind variations observed in the lower thermosphere over the South Pole Journal Article uri icon

Overview

abstract

  • Abstract. The first meteor radar measurements of meridional winds in the lower thermosphere (about 95 ± 5 km), along four azimuth directions: 0°, 90°E, 180° and 90°W; approximately 2° from the geographic South Pole were made during two observational campaigns: January 19, 1995-January 26, 1996, and November 21, 1996-January 27, 1997. Herein we report analyses of the measurement results, obtained during the first campaign, which cover the whole one-year period, with particular emphasis on the transient nature and seasonal behavior of the main parameters of the intradiurnal wind oscillations. To analyze the data, two complementary methods are used: the well-known periodogram (FFT) technique and the S-transform technique. The most characteristic periods of the intradiurnal oscillations are found to be rather uniformly spread between about 7 h and 12 h. All of these oscillations are westward-propagating with zonal wave number s=1 and their usual duration is confined to several periods. During the austral winter season the oscillations with periods less than 12 h are the most intensive, while during summer season the 12-h oscillations dominate. Lamb waves and internal-gravity wave propagation, non-linear interaction of the short-period tides, excitation in situ of the short period waves may be considered as possible processes which are responsible for intradiurnal wind oscillations in the lower thermosphere over South Pole.Key words: Meteorology and atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics; waves and tides);

publication date

  • January 1, 2000

has restriction

  • gold

Date in CU Experts

  • April 21, 2014 4:24 AM

Full Author List

  • Portnyagin YI; Forbes JM; Merzlyakov EG; Makarov NA; Palo SE

author count

  • 5

Other Profiles

Electronic International Standard Serial Number (EISSN)

  • 1432-0576

Additional Document Info

start page

  • 547

end page

  • 554

volume

  • 18

issue

  • 5