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Zonally uniform tidal oscillations in the tropical stratosphere
Author(s) -
Sakazaki Takatoshi,
Sasaki Takuya,
Shiotani Masato,
Tomikawa Yoshihiro,
Kinnison Douglas
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl066054
Subject(s) - stratosphere , equator , atmospheric sciences , northern hemisphere , climatology , atmospheric tide , amplitude , southern hemisphere , universal time , geology , environmental science , physics , latitude , geophysics , geodesy , ionosphere , thermosphere , quantum mechanics , astronomy
By analyzing data from satellite measurements, a reanalysis, and a chemistry‐climate model, we found clear zonally uniform tidal signals in the tropical stratosphere, particularly during the Northern Hemisphere summer. Antisymmetric components with respect to the equator are dominant and are characterized by a vertical wavelength of ~15 km and a diurnal frequency. The temperature and vertical wind diurnal amplitudes in the stratosphere are 0.2–1 K and 1–7 mm s –1 , respectively. The latter is generally larger than the climatological ascent motion in the stratosphere. The observed latitudinal and vertical structures can be explained by the second, propagating, antisymmetric Hough mode. These tidal oscillations should be carefully considered in analyses of zonal mean fields at a particular universal time.