SeaWiFS image indicating chlorophyll bloom
SeaWiFS data showing source of terrestrial plume

Plumes & Blooms

An ocean color assessment of the Santa Barbara Channel

Each year, winter rains wash sand, mud and other terrestrial debris into the Santa Barbara Channel. Then, during the spring and summer, phytoplankton populations increase dramatically and ultimately provide the primary energy source for the entire marine food web. These alternating patterns of brown terrestrial ‘plumes’ and green algal ‘blooms’ provide UCSB ocean color scientists with an excellent field laboratory for understanding and modeling the color of the ocean. By capitalizing on the most recently available satellite imagery, we can then identify the spectral characteristics of the reflected light from the ocean’s surface and directly relate it to the particulates and dissolved materials in it during these conditions. In the end, these numerical algorithms will be extremely useful for ocean scientists as well as fisheries and coastal zone managers.

The Blooms and Plumes program is a joint collaboration among UCSB faculty, student and staff researchers at the Institute of Computational Earth System Science (ICESS), NOAA researchers at the Coastal Services Center (Charleston, SC) and the NOAA sanctuary managers of the Channel Islands National Marine Sanctuary (CINMS). Since August, 1996, we have been conducting monthly research cruises in order to collect measurements for our in-situ database. These measurements include temperature and salinity, ocean color spectra, and water column profiles of red light transmission and chlorophyll fluorescence (indexes of suspended particulate load and phytoplankton abundance). The transect observations begin at the shelf waters north of Santa Rosa island and end at an area off Goleta Point. By combining these repeat observations with satellite imagery, we can build a time-series of the changing ocean color conditions in the Santa Barbara Channel.

Knowledge of the composition, concentration, and origin of suspended and dissolved materials in the U.S. coastal ocean is critical for properly monitoring marine resources and evaluating the impact of human activities. Detailed ocean color modeling activities are required if coastal zone managers are to take advantage of the global investments made in satellite-borne ocean color sensors. The Plumes and Blooms project is a good first step towards this goal.