Enhancing Information Content in the Satellite-Derived Daytime Infrared Sea Surface Temperature Dataset Using a Transformative Approach

Prabhat K Koner

doi:10.3389/fmars.2020.556626

Abstract

The operational daytime Sea Surface Temperature (SST) retrieval from remote sensing Infrared (IR) measurements does not conventionally use Mid-Wave IR (MWIR) channels due to solar contamination. However, MWIR channels are desirable to obtain unambiguous surface information and a transformative approach, Physical Deterministic Sea Surface Temperature (PDSST) retrieval scheme, including MWIR channels, to enhance the information content in satellite-derived SST data. This paper mainly emphasizes on the quality and availability of swath-processed daytime SSTs from MODIS-AQUA radiances using PDSST suite, including MWIR channels, for coastal and near-coastal areas, which are needed the most. The focus areas of this study are the California coast, which is a highly dynamic oceanographic region, the Indian Ocean, which has a sparse population of in-situs, and the Chesapeake Bay, which is best known for seafood production. Apart from in-situ validation using iQuam (NOAA), indirect validation, by comparing different SST products, is also performed. The results of PDSST-suite are compared with the currently operational MODIS-AQUA SSTs, obtained from the NASA website, and microwave SSTs from AMSR2, obtained from RSS website. Both the operational products are based on the regression method. It is found that the PDSST suite including MWIR channels can extract 3-5 times as much information as the currently operational NASA-produced regression-based daytime SSTs from MODIS-AQUA radiances for coastal areas.

Highlights

Sea Surface Temperature (SST) is one of the crucial variables in the earth science modeling
The Data Coverage (DC) of RGSST5 for Madagascar Coast (MC) is higher than the same for California Coast (CC) and the value of information gain of Physical Deterministic SST retrieval (PDSST) over RGSST5 is low. This implies that the Quality Flag (QF) procedure for RGSST5 is more stringent for coastal areas because the set of granules for MC is from the deeper parts of the ocean than the same for CC
The swath-processed SSTs using the PDSST suite on MODISAQUA radiance data for coastal and near-coastal areas reveal that enhanced SST information can be obtained using Mid Wave Infrared (MWIR) channels in the daytime SST retrieval scheme

Summary

INTRODUCTION

Sea Surface Temperature (SST) is one of the crucial variables in the earth science modeling (e.g., numerical weather prediction, ocean circulation modeling, air−sea interactions, marine ecosystems, upwelling regions, boundary currents, planetary boundary layer divergence, ocean biology, including coral reefs and algae blooms) A subset of RGSSTs from MODIS-AQUA, RGSSTP, is obtained using the cloud-free pixels according to the PDSSTsuite for the following comparison study Both PDSST and RGSSTP are re-gridded to the MWSST grid and differences from MWSST are plotted in Figures 7B,C, respectively. There is no correlation between the QF values from the RGSST product and realistic cloud-free conditions

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT