The distribution and spectral properties of colored dissolved organic matter (CDOM) in the northern Bay of Bengal were investigated in June 2016. Based on in situ data collected from 100 CDOM samples at 25 stations, the distribution characteristics of CDOM in the surface layer differed markedly from those at 30 m, 75 m, and 100 m. The CDOM spectral slope (S350−500) exhibited a broad range, varying from 0.0026 to 0.0300 nm−1, and showed a significant negative correlation with the absorption coefficient aCDOM(443). Analysis of salinity and temperature profiles revealed no obvious correlation between the distribution of aCDOM(443) and these physical parameters. A comparative analysis with satellite-derived wind and current data indicated that elevated aCDOM(443) values in the northeastern surface waters were primarily associated with the southwest monsoon. In contrast, aCDOM(443) values in the lower mixed layer were mainly influenced by the combined effects of geostrophic and eddy currents.
Wu et al. (Fri,) studied this question.