Oceansat Chlorophyll a Imagery

The Louisiana coast receives large volumes of river water from the Mississippi and Atchafalaya Rivers. The rivers usually flood in spring and sometimes into summer, producing a stratified water column. The river-borne nutrients fuel large phytoplankton blooms on the shelf. These physical and biological processes can result in hypoxia on the shelf, and the "dead zone".

Chlorophyll a image of SE Louisiana river diversions (inset Fig)

The Ocean Color Monitor (OCM), with 8 spectral bands similar to NASA's SeaWiFS sensor, is used to estimate chlorophyll a concentrations as well as to quantify suspended sediments. "True color" enhancements can provide additional information on cloud cover, water mass color/types, vegetation health, and bottom type. The fate of river waters and the location of ocean eddies can be determined using various channels and channel combinations from "ocean color sensors". One big advantage of the OCM sensor is that its pixels are 360m, in contrast to SeaWiFS and MODIS which have 1 km pixels.

It is important to clarify that satellite-derived chlorophyll measurements can be effected by CDOM, suspended sediments, and bottom reflectance. Thus, caution should be taken when interpreting the patterns in coastal waters.

Recent Imagery

Note: The most recent 8 days of OCM images are not published.

Latest Images

      Gulf OF Mexico   		     Louisiana Coast Region              Swath
           

      Atchafalaya Bay		     Mississippi Region
          

OCM Chlorophyll Image Archive