A wave investigation in the tropical Atlantic Ocean using satellite altimetry data and Hilbert transform based methods
Event: 2014 Ocean Surface Topography Science Team Meeting
Session: Science Results from Satellite Altimetry: Regional and basin-scale processes and sea level rise
Presentation type: Type Poster
Contribution: not provided
We explore the characteristics of these waves with Hilbert transform based methods. These techniques allow us to estimate the instantaneous amplitude, period, and speed of the propagations. We show that these quantities are correctly estimated, and are physically valid if the signals are asymptotic, and are decomposed in their high (from 2 to ~8 weeks), and low (from ~8 to 52 weeks) frequency asymptotic components. For this purpose we develop a filtering technique based on the Empirical Mode Decomposition method. The estimated mean speed of the propagating waves are ~19 cm/s, for the eddies close to the brasilian coast, ~50 cm/s, for the instability waves at 4°N, ~181 cm/s, for the Kelvin waves at the Equator, ~61 cm/s for the Rossby waves at 3°N, and ~48 cm/s at 3°S. All of these waves are characterized by the presence of a strong annual cycle in their instantaneous amplitude, and speed.