Modulations of the phase speed of convectively coupled Kelvin waves by the ITCZ

Juliana Dias, Olivier Pauluis

Research output: Contribution to journalArticle

Abstract

A number of studies suggest a two-way feedback between convectively coupled Kelvin waves (CCKWs) and the intertropical convergence zone (ITCZ). Viewed here as a proxy for deep convection, analysis of brightness temperature data reveals several aspects of these interdependencies. A wavenumber-frequency spectral analysis is applied to the satellite data in order to filter CCKWs. The ITCZ is characterized by a region of low brightness temperature and a proxy for both the ITCZ location and width are defined. The phase speed of CCKW data is determined using the Radon transform method. Linear regression techniques and probability density analysis are consistent with previous theoretical predictions and observational results. In particular, the fastest waves are found when the ITCZ is the farthest from the equator and the narrowest. Conversely, the slowest waves coincide with broad ITCZs that are located near the equator.

Original languageEnglish (US)
Pages (from-to)1446-1459
Number of pages14
JournalJournal of the Atmospheric Sciences
Volume68
Issue number7
DOIs
StatePublished - Jul 2011

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Kelvin wave
intertropical convergence zone
brightness temperature
Radon transform
spectral analysis
satellite data
convection
speed
filter
prediction

Keywords

  • Feedback
  • Intertropical convergence zone
  • Kelvin waves
  • Satellite observations

ASJC Scopus subject areas

  • Atmospheric Science

Cite this

Modulations of the phase speed of convectively coupled Kelvin waves by the ITCZ. / Dias, Juliana; Pauluis, Olivier.

In: Journal of the Atmospheric Sciences, Vol. 68, No. 7, 07.2011, p. 1446-1459.

Research output: Contribution to journalArticle

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