A new mapping method for propagating data

Satellite altimetry data have been very useful in the study of oceanic eddies. However, eddies are only detected while they cross the satellite tracks but are missed when they are between tracks. A natural question is: should we use information of both time and space to do the data mapping? A new satellite data processing method combines propagating empirical orthogonal functions (EOF) analysis and an interpolation algorithm based on variance decomposition and maps the data into new time and/or space grids objectively. Here, as an example, the method is applied to the TOPEX/Poseidon along-track sea surface height (SSH) anomaly data. For each EOF mode, space and time information is obtained, and later mapped onto a finer grid. Finally, the field is reconstructed onto the new grid by summing the top several significant modes. The method was tested by performing three simple experiments and another experiment using synthetic SSH from a realistic high resolution model. Then a reconstruction of SSH from satellite data was applied to the Gulf of Mexico.