Intercomparison between Retracked Sea Levels from SARAL/AltiKa Satellite Altimetry and Ocean Data Model over the Maginal Seas at the South East Asia.

Abstract

In this paper, comparison between retracked sea levels from SARAL/AltiKa satellite altimetry with the data model from the Coriolis Data Centre is performed. The study focuses on the Marginal Seas at the South East Asia, which includes the Straits of Malacca, the South China Sea and the Sulu Sea. The SARAL/AltiKa sea level is based on the standard ocean (i.e. Maximum Likelihood, MLE4) retracker. The analysis is performed by computing the correlation coefficient and root mean square (RMS) error during the north-east and south-west monsoon seasons in 2014-2015. In comparison with the data model, both datasets have high (greater than or equal to 0.8) correlation coefficient and low (less than or equal to 61 cm) RMS error over the South China Sea during both monsoon seasons. In contrast, the Sulu Sea has low (less than or equal to 0.5) correlation and high (greater than or equal to 56 cm) RMS error during both seasons. It can be concluded that the accuracy of the datasets really depends on the coastal topography of the ocean region itself. More complex regions have greater influence on the altimetry observations, thus reducing the accuracy of the estimations.