Indian Ocean Rossby waves observed in TOPEX/POSEIDON altimeter data and in model simulations

Analysis of 3 years of TOPEX/POSEIDON (T/P) altimeter data in the Indian Ocean revealed discrepancies between observed and theoretical Rossby wave phase speeds. Rossby waves were observed at all latitudes using Hovmoller diagrams or longitude/time plots; their phase speeds were computed using twodimensional Fast Fourier Transforms (FFTs). Complex Principal Component Analysis (CPCA) was applied to detect travelling waves. A simple wind-driven layer model was implemented for this region and forced with the ERS-1 scatterometer winds, sampled over the same period as the T/P data, to demonstrate that these winds account for much of the observed Rossby wave activity.

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