Spatial correlations between ATSR sea surface temperature and altimetric sea surface height

Abstract

In recent years altimetric measurements of sea surface height (SSH) and infrared radiometric measurements of sea surface temperature (SST) have provided a wealth of information about ocean circulation and atmosphere/ocean interactions. SSH is a depth integrated quantity depending on both the temperature/salinity structure of the water column and the depth independent barotropic contribution. SST from infrared radiometers is a purely surface parameter representing the temperature of the top few microns of the ocean surface. Hence any relationship between SST and SSH is providing information on surface/subsurface coupling. Establishing the extent to which SST and SSH are related could lead to new techniques such as interpolation of SSH data with SST, improving eddy statistics, and providing new dynamical information about the coupling between the ocean surface and subsurface. We use SST data from the Along-Track Scanning Radiometer (ATSR) to examine the relationship between SST and SSH anomalies (from temporal means). It is found that zero-lag spatial cross correlations between SST and SSH anomalies are surprisingly strong (~0.7) in specific geographical locations associated with mesoscale variability. The correlations are seasonal being strongest in winter months and weakest in summer months. A scale analysis of the correlations suggests that they are mainly due to features with wavelengths ~600km implying that large meanders in ocean fronts and/or mesoscale eddies could be responsible. We discuss the implications of these correlations and demonstrate various techniques requiring the synergistic use of SSH and SST data.

Keywords: ATSR,TOPEX/POSEIDON,ERS-1,Sea Surface Temperature, Sea Surface Height