Evaluation of the precision in level-2 avhrr sea surface temperature fields

Document Type

Conference Proceeding

Date of Original Version



The accuracy of satellite-derived sea surface temperature (SST) fields has drawn a great deal of attention, while little attention has been focused on the spatial precision. Very limited information of the uncertainty in pixel-to-pixel scale in the retrievals is provided by satellite in-situ matchups, which are widely separated in space and time because of cloud cover and the lack of in-situ observation. But the main contribution to the uncertainty in satellite retrievals results from atmospheric contamination - the spatial scale of which is, in general, large compared with the pixel separation of infrared sensors, hence the pixel-to-pixel uncertainty is often smaller than the accuracy determined from in-situ matchups, this makes selection of satellite-derived datasets for the study of submesoscale processes, for which the spatial structure of the upper ocean is significant, problematic. In this study, we develop an approach to evaluate the spatial fidelity of Advanced Very High Resolution Radiometer (AVHRR) SST fields, the spatial power spectra density (PSD) of which are compared with an in-situ measurement in Sargasso Sea. We found AVHRR spectra have elevated energy at the submesoscale, and the spectra tend to level off at smaller scale results from the instrument noise, the level of which is estimated based on the spectra comparison.

Publication Title, e.g., Journal

International Geoscience and Remote Sensing Symposium (IGARSS)