A harmonic analysis of 100 mb zonal winds in the tropics

Authors

  • J. M. WALKER

DOI:

https://doi.org/10.54302/mausam.v26i2.2141

Keywords:

Fourier analysis, zonal-wind velocity, easterlies, upper-wind patterns

Abstract

Monthly-mean 100 mb zonal wind observations from stations in, or on the fringe of, the tropics have been subjected to Fourier analysis.

        Annual and semi-annual harmonics are evident at many stations, and superpositions of these two harmonics reproduce observations quite well at these stations. Dates corresponding to greatest rates of change of zonal-wind velocity coincide well with the onset and retreat of summer monsoon circulations, except over the western North Pacific Ocean, where the annual harmonic behaves rather differently from elsewhere. It is clear that upper easterlies associated with summer monsoon circulations influence upper-wind patterns well beyond those areas generally considered to be monsoonal on the basis of rainfall and surface-wind reversals.

 

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Published

01-04-1975

How to Cite

[1]
J. M. . WALKER, “A harmonic analysis of 100 mb zonal winds in the tropics”, MAUSAM, vol. 26, no. 2, pp. 181–188, Apr. 1975.

Issue

Section

Research Papers