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Comparison of mesospheric wind spectra with a gravity wave model
Author(s) -
Smith Steve A.,
Fritts David C.,
VanZandt Thomas E.
Publication year - 1985
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs020i006p01331
Subject(s) - mesopause , mesosphere , gravity wave , stratosphere , amplitude , physics , spectral line , atmospheric sciences , wavenumber , geology , zenith , gravitational wave , geodesy , optics , astrophysics , astronomy
We present radial wave number spectra of wind fluctuations obtained from heights near the mesopause by the Poker Flat, Alaska, mesosphere‐stratosphere‐troposphere (MST) radar running in a high spatial resolution mode (300 m). The spectra are of radial wind fluctuations along one vertical and two oblique (15° zenith angle) beams measured at heights of 82–88 km during summer. The oblique wave number spectra have amplitudes that are within a factor of 3 of each other and appear to follow power laws with exponents in the −2 to −2.8 range. In order to infer what portion of the spectral amplitude can be attributed to gravity waves, the ratio of oblique to vertical amplitudes is compared with the ratio predicted by the gravity wave model of VanZandt. The observations are found to be consistent with the model, suggesting that gravity waves are the dominant motion in the high‐latitude summer mesosphere.