Submesoscale variability from satellite thermal imagery: preliminary results

Here we report first results of an investigation of submesoscale features in ocean thermal imagery and their relationship to the mesoscale, the seasonal cycle, and surface wind stress. Spectra and other metrics are extracted from a twenty-year archive of thermal imagery from the East Australian Current, a western boundary current of the South Pacific, to quantify the range of scales and their time evolution. These metrics and mesoscale velocities from ocean reanalysis products are used to examine relationships between the submesoscale and mesoscale. Effects of seasonal variations in the mixed layer depth on the submesoscale are investigated by comparing observations from summer and winter imagery. The overall use of thermal imagery for investigating the submesoscales is assessed, in particular the use of single channel imagery versus multi-channel SST, the effects of resolution changes due to satellite scan angle, and the amount of information that can be extracted with intermittent cloud cover.