Spatial Correlations: A Measure of the Relationship Between SST Fronts and Bottom Topography.

Yackar Mauzole and Peter Cornillon, University of Rhode Island, Graduate School of Oceanography, Narragansett, RI, United States
Abstract:
Past studies have suggested that bottom topography may play an important role in the spatial distribution of sea surface temperature (SST) fronts. In this study we compare maps of front probability and mean SST gradient (at the frontal locations) with the bathymetric gradient. Front probability and mean SST gradients are based on fronts detected by a slightly modified version of the Cayula-Cornillon algorithm applied to the Level 3 Advanced Very High Resolution Radiometer (AVHRR) 4km Pathfinder SST dataset (1982-2011) between 60°S and 60°N. The correlation between front probability and bathymetry shows that a substantial fraction of submesoscale and mesoscale SST fronts are detected at locations where the bathymetric gradient is significant, with the correlation being particularly strong for coastal fronts, but also observable for the equatorial frontal systems off South America and Africa and for Subpolar fronts. The correlation between mean SST
gradient at frontal locations and bathymetry shows that, with the exception of regions associated with strong, large scale currents, such as the ACC and the Gulf Stream, the larger the gradient the tighter the correlation. The seasonal variability of these correlations is also discussed.