Spatial Variation Of Cdom And Its Influencing Factors In Tropical East Indian Ocean During Summer

The colored dissolved organic matter, abbreviated as CDOM, is an important ingredient that affects the light absorption characteristics of seawater, and one of the key elements for ocean color research. In the case of only few focus on temporal and spatial variation of CDOM in tropical East Indian Ocean, this paper analyzes the CDOM spectral characteristics of this area based on the optical data of the summer survey in Southeast Indian Ocean in 2016, the variation and the related factors affecting the CDOM absorption characteristics of this area by using MODIS/VIIRS satellite remote sensing data. The results shows that 1) the CDOM absorption spectrum meets quasi-exponential decay characteristics, and the surface a(g) (440) changes from 0.002 to 0.098 m(-1), which is smaller than that of inshore water is larger than that of Southeast Pacific Ocean; 2) a(g) (440) in 8 degrees S is significantly greater than 5 degrees S, and the maximum appears in the southwest of the observation area (88 degrees E, 8 degrees S); 3) above the shallow depth of 100m, a(g) (440) tends to increase with depth; 4) the distribution of surface CDOM absorption coefficient shows significant consistency with chlorophyll concentration (r=0.8495), while not related to sea surface temperature (r=0.0064). CDOM and chlorophyll have similar driving mechanisms in the research area. The spatial distribution of CDOM is influenced by the subaqueous equatorial currents, the low-temperature waters from the Southern Ocean, and short-term small-scale effects, while the profile distribution is related to light field and nutrients. This study provides a further reference for understanding the optical properties of tropical waters in the East Indian Ocean.