Dr. Ajit Subramaniam
Earth Institute Contact: Dr. Ajit Subramaniam
Locations: United States of America
River runoff of dissolved organic carbon (DOC) into the oceans is significant and can play a very important role in the global carbon cycle being that the carbon reservoir of DOC in the ocean is comparable to that of CO2 in the atmosphere. A fraction of DOC – Chromophoric Dissolved Organic Matter (CDOM) – is capable of absorbing visible and ultraviolet light and hence can be detected by ocean color satellite sensors. Various investigators have reported a relationship between DOC concentrations and absorption by CDOM, but the parameterization of this relationship appears to vary regionally and seasonally due to photochemistry.
This project will investigate the relationships between DOC and CDOM, and between carbon and ocean color. Data from historical and ongoing fieldwork will be used to study the spatial and seasonal distribution of DOC, along with inherent and apparent optical properties, for the coastal and continental shelf regions along the east coast of the U.S. We also intend to further investigate photodegradation of DOC to dissolved inorganic carbon (DIC) during summertime and link it to bleaching of CDOM. The combined dataset will be used to develop an algorithm to map DOC from the DOC-to-CDOM dependence using satellite ocean color sensors. Yearly time-series of DOC maps for the east coast of the U.S. will be constructed, thus allowing us to explore the spatial and temporal variability, as well as long-term changes if any, in this parameter with strong emphasis on the processes driving DOC distribution, transformation and transport. This proposal addresses an area of primary interest for NASA in the North American Carbon program by bringing remote sensing to bear on characterization of carbon stocks, transport and transformations of terrestrially derived organic carbon in the coastal waters off the eastern United States.
The goals of the proposed research are to map DOC (and terrigenous CDOM) and to compile a long-term dataset to that will allow us to better define the processes driving the distribution, transformation and transport of dissolved organic carbon in the coastal ocean off the eastern U.S.
Cross Cutting Themes:
Climate and Society
Project Web Site: