The Labrador Sea plays a critical role in ocean physics and biogeochemistry. It is a region of deep water formation, and experiences an intense phytoplankton bloom that peaks in the second half of June. This bloom makes the region a significant sink of carbon dioxide (CO2) from the atmosphere. In contrast to other sink regions of the global ocean that return to the surface on shorter (decadal) time scales, atmospheric CO2 sequestered in waters of the Labrador Sea are removed from contact with the atmosphere for millennia. Recently, the NSF Physical Oceanography and Chemical Oceanography Programs funded researchers at several institutions to study the dynamics of the physicochemical sequestration of CO2 in the Labrador Sea - but not the biological aspects.
In this project, researchers at the Oregon State University will enhance the ongoing Labrador Sea study by adding a study of CO2 drawdown during the spring plankton bloom. The seasonally high primary productivity of the region is partially responsible for its status as a CO2 sink, so it is essential to quantify the biological carbon uptake. Doing so requires estimates of community biomass, productivity and export. Furthermore, the physical and ecological processes controlling the spring bloom - mixing, light, grazing - are of interest in and of themselves. The sub-daily time series of pCO2 and DO, already funded, is rich in biological information, but cannot be fully exploited without the additional biological parameters contributed by this proposal. Thus this project involves a synergy between a study of gas fluxes, which will benefit from biological measurements, and a study of biological processes, which will benefit from the detailed chemical flux measurements.
Broader impacts: This work addresses a problem of global societal concern, namely the exchange of CO2 between the ocean and atmosphere and the potential of the ocean to sequester CO2 at climatically significant time scales. During the course of the project, undergraduate students will gain experience in the analysis and interpretation of satellite data. The results of the program will be incorporated into graduate teaching and disseminated at scientific meetings and on the principal investigator's website.
