Regional optimization of an atmospheric correction algorithm for the retrieval of sea surface temperature from the Canary Islands–Azores–Gibraltar area using NOAA/AVHRR data

Abstract

An atmospheric correction algorithm for the retrieval of sea surface temperature (SST) from the Canary Islands–Azores–Gibraltar area is developed by using a matchup dataset from Advanced Very High Resolution Radiometer (AVHRR) multiple‐infrared window channel data and in situ SST data. The improvements and restrictions introduced in the systematic procedure to generate the matchup database lead to a very high quality comparison dataset. Regionally optimized algorithm coefficients, which take into account the large zenith angle variation over a whole AVHRR image, are estimated from multivariate analysis using 80 co‐located in situ and satellite measurements. For validation purposes 135 data from the AVHRR Pathfinder Oceans Matchup Database (PFMDB) are obtained. Error analysis shows that SST can be retrieved to within 0.5°C. A comparison with different regional and global algorithms shows that considerable improvement is achieved by regionally optimizing the algorithm coefficients. Finally, the performance of the proposed algorithm is assessed and applied to the AVHRR/3 sensor aboard NOAA‐L satellite using an independent in situ dataset, derived from the ARGO Data Collection System.

Acknowledgments

This work was supported by the Educational Council of the Canary Islands Government (Project 2002/063) and CORICA Project (REN 2001‐2649). This study has been carried out in the frame of the collaboration contract (No. 19452‐2002‐05 SOSC ISP ES) between the University of Las Palmas of Gran Canaria (ULPGC) and the Joint Research Council. The authors would like to thank J. L. Pelegrí (ICH‐CSIC) (ULPGC), and anonymous reviewers for their constructive comments and suggestions.