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Daily wind, pressure, and temperature variation up to 30 km over the tropical western Pacific
Author(s) -
Hastenrath S.
Publication year - 1972
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.49709841505
Subject(s) - diurnal temperature variation , atmospheric sciences , diurnal cycle , troposphere , amplitude , climatology , environmental science , variation (astronomy) , stratosphere , pressure gradient , atmospheric pressure , geology , meteorology , physics , quantum mechanics , astrophysics
The diurnal and semi‐diurnal variations of wind, pressure and temperature at 23 levels between 1,000 and 10 mb over eight stations in the tropical western Pacific are obtained by combining six‐hourly soundings taken at different times in April‐July 1956 and 1958. Results of all stations are combined according to local time. The prevalence of the semi‐diurnal pressure wave in the lower layers gradually yields to the first harmonic in the upper troposphere and stratosphere, as a consequence of the predominantly diurnal variation of temperature. The semi‐diurnal variation of temperature is found to increase slightly with height. Increase of the second harmonic amplitude of the u and v wind components with height is roughly proportional to the decrease of air density, with the phase remaining nearly constant, except for the lower layers. The phase relationship between the semi‐diurnal variations of pressure, and eastward and northward directed wind components is discussed in terms of a model based on a linearized form of the equations of motion, frictionless flow, and the assumption that the oscillations are simple progressive waves.