In complex waters, it is still a challenge to develop ocean color retrieval methods with high accuracy. In this work, we improved an Empirical Orthogonal Function (EOF) method with Equal Dimension New Information (EDNI) to retrieve chlorophyll a concentration (CHL) and phytoplankton absorption coefficient (aph(675)). EDNI was introduced to trace the variations in time-series data. EOF, combined with EDNI, helped to catch input parameters. The data used in this work were collected by optical buoy during a whole red tide in the Zhujiang (Pearl) River Estuary in August 2007. The average absolute percentage difference (APD) of CHL was 29.6%, which was smaller than those from other empirical algorithms. The APD of aph (675) were 23.8%, which was better than those from QAA_v5. In addition, we compared the results with those without EDNI, and found that the APDs of CHL and aph (675) without EDNI increased by about 20%.
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