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Evidence of geostrophic motion in the equatorial stratosphere
Author(s) -
Reed R. J.
Publication year - 1962
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49708837711
Subject(s) - geostrophic wind , equator , oscillation (cell signaling) , stratosphere , thermal wind , amplitude , atmospheric sciences , physics , acceleration , geology , magnitude (astronomy) , geodesy , mechanics , meteorology , wind speed , latitude , wind shear , classical mechanics , astrophysics , quantum mechanics , biology , genetics
Abstract The characteristics of the temperature oscillation associated with the recently discovered 26‐month oscillation of the zonal wind component in the equatorial stratosphere are inferred from the thermal wind relationship. Computations based on actual wind data predict an amplitude of 2·5°C for the temperature oscillation near the equator and a phase difference of one to two months between wind and temperature cycles at 20 km increasing to seven months at 24 km. The close correspondence between predicted and observed characteristics supports the hypothesis that the 26‐month oscillation is in geostrophic equilibrium. The hypothesis is also supported by a consideration of relative sizes of the local wind acceleration and Coriolis force which indicates that the acceleration becomes an order of magnitude less than the Coriolis force at a distance of 40 km from the equator.