Sea Surface Current Retrieval From Sequential SAR and Ocean Color Images for Eddy Kinematics Analysis: A Case Study in the Northern Tyrrhenian Sea

Abstract

Sea surface currents (SSCs) are of great importance in monitoring the evolving dynamics of oceans and can be effectively obtained from sequential remote sensing images. However, the absence of traceable feature patterns in sequential remote sensing images constrains the capabilities for retrieving SSCs. In this article, an approach was presented to retrieve SSCs by merging currents derived from synthetic aperture radar (SAR) and ocean color (OC) images computed using the maximum cross-correlation (MCC) method. For different OC product performances in retrieving the surface currents, an evaluation criterion was used to select the optimal OC-derived currents before merging. The complete current field was obtained by merging SAR and optimal OC-derived currents based on the correlation coefficient weighted model. Statistical comparisons were performed between the merged and geostrophic currents obtained from the altimetry over the northern Tyrrhenian Sea. The two current fields were in good agreement, with a complex correlation coefficient of 0.65 in magnitude and 2.23° in phase. The oceanic eddy kinematic parameters were successfully calculated based on the complete current field obtained and used to analyze spatio-temporal evolution characteristics.

Keywords

• Ocean color (OC)
• oceanic eddies
• sea surface currents (SSCs)
• synthetic aperture radar (SAR)