Validation of satellite sea surface temperature information with in situ records within 60 miles of the Peruvian sea

Abstract

In situ recordings and satellite information from different sensors including post-processing are used to monitor the thermal conditions of the Peruvian coastal system. The satellite information databases, which had a greater approximation to in situ records, were identified with error and dispersion parameters and the SST estimates in strips adjacent to the coast were evaluated in terms of error to see the effect of the coast-to-ocean location. Satellite information was taken from the AVHRR, MW, MW-IR, NAVOCEANO, MUR, and OSTIA databases and in situ records were taken from research and monitoring cruises in fixed-point sections conducted between 2014 and 2016. It was found that compared to records in cruises, the OSTIA database presented, on average, less error (RMSD=0.625) and less dispersion (SD=1.855) at distances of 10-20 and 20-30 nm offshore, indicating greater accuracy and precision, while compared to records in sections-fixed points, MUR presented less error (RSMD=0.715) and OSTIA less dispersion (SD=1.948) showing, respectively, greater accuracy and precision than the other satellite databases. In the coast-to-ocean gradient, the SST estimates for most of the satellite information databases showed a higher level of error in stripes near the coast (0-10 nm) and a lower error in more distant stripes (30-60 nm). The error decreased from coast to ocean both as opposed to records on cruises (mean MAE from 0.96 to 0.26), and as opposed to records in fixed-point sections (mean MAE from 1.06 to 0.41). OSTIA and MUR presented SST estimates with a better approximation to the in situ SST.