Observations of mesospheric wind velocities: 1. Gravity wave horizontal scales and phase velocities determined from spaced wind observations

Authors

  • C. E. Meek,

  • I. M. Reid,

  • A. H. Manson


Abstract

Horizontal scales and phase velocities of upper middle atmosphere (60–110 km) gravity waves determined from preliminary analysis of spaced wind observations obtained with a dual bistatic radar (Gravnet), based on and operated together with the Saskatoon MF radar are presented. In the observed period range of 10–100 min, horizontal scales increase from values of ∼44 km at 10 min to ∼211 km at 100 min, while observed phase speeds decrease from values of ∼72 m/s at 10 min to ∼34 m/s at 100 min. Typical rms perturbation velocities are ∼5 m/s. Calculation of intrinsic wave parameters indicates that in the intrinsic period range of 10–100 min, horizontal scales increase from values of ∼68 km at 10 min to ∼119 km at 100 min, with intrinsic phase speeds of ∼93 m/s at 10 min and ∼20 m/s at 100 min. The corresponding values of vertical wavelength are 30 km and 6 km, respectively.

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