Comparison between Argo-derived sea surface temperature and microwave sea surface temperature in tropical Indian Ocean

Abstract

A comparison between in situ and microwave satellite-derived sea surface temperature (SST) for the tropical Indian Ocean (TIO) during January 2009–December 2010 is presented. All available in situ temperatures close to the surface (∼5 m) from Argo profiling floats are used in this study. Weekly 0.25° × 0.25° spatial resolution SST was produced from these Argo in situ data using the Data-Interpolating Variational Analysis (DIVA) method. This weekly Argo sea surface temperature (ASST) is compared with Tropical Rainfall Measuring Mission Microwave Imager (TMI)-retrieved Sea Surface Temperature (TMISST) and available blended Optimum-Interpolation Sea Surface Temperature (OISST) product, at selected regions encompassing the north, central and southern TIO. The results indicate a bias and root mean square error (RMSE) of –0.02°C and 0.45°C between ASST and OISST, whereas the bias and RMSE between ASST and TMISST is observed to be 0.11°C and 0.32°C, respectively. The correlation coefficient (r) between ASST and OISST is observed to be 0.980, whereas r between ASST and TMISST is observed to be 0.985.

Acknowledgements

The authors thank the Director, INCOIS, for encouragement and for providing the necessary infrastructure to carry out this work. The comments by the anonymous referees and the editor Dr Tim Warner have improved the quality of the article significantly. Argo data are made available freely by the International Argo Community. TMI data are produced by Remote Sensing Systems and sponsored by the NASA Earth Science MEaSUREs DISCOVER Project. Data are available at www.remss.com. OISST data are obtained from NOAA, USA. The research leading to the development of DIVA has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n°283607, SeaDataNet 2. This is INCOIS contribution number 117.