Wintertime Air-Sea Heat and Carbon Exchange in the Gulf Stream Observed with an Autonomous Wind-powered Surface Vehicle
The second annual Saildrone Award 30-day mission was awarded to a team led by Dr. Jaime Palter at the University of Rhode Island to study Western Boundary Currents, starting in early 2019.
Western Boundary Currents, for example, the Gulf Stream, endure the most intense air-sea heat exchange and the strongest CO2 uptake in the world ocean. Because of the short space and time scales characterizing their variability, they present tremendous observing challenges that are not easily addressed with traditional methods. Thus, their contribution to the global ocean carbon budget remains poorly quantified. Saildrone provides a platform capable of long-endurance, high-speed, accurate lower atmosphere, and surface ocean measurements.
The team will use a saildrone to measure wintertime surface heat and CO2 fluxes across the Gulf Stream. Despite a rich history of observations, the proposed mission will provide the most detailed data on the wintertime evolution of CO2 in the Gulf Stream from Cape Hatteras North Carolina to a position about 1,000 kilometers offshore. With these observations, the scientists will answer a number of open questions about the rate and location of the CO2 uptake in the Gulf Stream and nearby regions, the driving mechanisms, and the response to anthropogenic emissions. Moreover, we will use the lessons we learn in the Gulf Stream to evaluate the capability of Saildrone to provide an observing strategy for more remote and chronically under-sampled Western Boundary Currents in other parts of the ocean.
This project addresses a key scientific question with immense societal value: Quantifying the ocean carbon sink is a grand challenge for oceanographers in a time of global change, and the Western Boundary Currents are frontier regions for such quantification. The work with Saildrone to quantify CO2 uptake and understand its key controls in the Gulf Stream will provide a necessary proof-of-concept test of a novel observing strategy. In so doing, Dr. Palter hopes to provide a path forward to help close the global carbon budget.