Multi-year satellite observations of instability waves in the Tropical Atlantic Ocean

[摘要] Instability waves in the tropical Atlantic Ocean are analysed bymicrowave satellite-based data spanning from 1998 to 2001. This isthe first multi-year observational study of the sea surfacetemperature (SST) signature of the Tropical Instability Waves(TIW) in the region. SST data were used to show that the wavesspectral characteristics vary from year-to-year. They also vary oneach latitude north of the equator, with the region of1° N, 15° W concentrating the largestvariability when the time series is averaged along the years.Analyses of wind components show that meridional winds are moreaffected near the equator and 1° N, while zonal windsare more affected further north at around 3° N and4° N. Concurrent observations of SST, wind,atmospheric water vapour, liquid cloud water, precipitation ratesand wind were used to suggest the possible influence of thesewaves on the Intertropical Convergence Zone (ITCZ). It seems thatthese instabilities have a large impact on the ITCZ due to itsproximity of the equator, compared to its Pacific counterpart, andthe geography of the tropical Atlantic basin. These analyses alsosuggest that the air-sea coupling mechanism suggested byWallace can also be applied to the tropical Atlanticregion.

[学科分类] 海洋学与技术