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Zonal wind quasi‐biennial oscillations at 25–60 km altitude, 1962–69
Author(s) -
Groves G. V.
Publication year - 1973
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.49709941907
Subject(s) - latitude , equator , altitude (triangle) , amplitude , oscillation (cell signaling) , atmospheric sciences , geology , range (aeronautics) , middle latitudes , climatology , environmental science , geodesy , physics , mathematics , geometry , materials science , quantum mechanics , biology , composite material , genetics
Meteorological rocket observations of zonal winds at thirteen sites (or pairs of sites) have been analysed for amplitudes and phases of their quasi‐biennial oscillation. The period of the oscillation was taken to be 32 months because from 1962–69 the period was relatively constant, not varying by more than ±3 months. Amplitudes and phases of the oscillation over a wide range of latitude are presented and discussed. The low‐latitude part of the oscillation is well‐defined with maximum amplitudes at 25 to 30 km altitude, which reach about 25 ms −1 at the Equator and decrease to a few ms −1 at 20° latitude. At other latitudes, amplitudes are less than 5 ms −1 except above 50 km at two sites between 50° and 60° latitude, where another main part of the oscillation is indicated. More observations and sites are needed at mid and high latitudes. Observations at the highest latitude site (77°) show no evidence of a diminished amplitude. Phases also depend on height and latitude and may reach gradients of 1 month km −1 with height and 2 months deg −1 with latitude respectively.