Presenter: Sarah Nickford (Univerity of Rhode Island)

Description:
Many large-scale estimates of air-sea CO₂ exchange rely on interpolation techniques and model reanalysis products. While these techniques and tools have provided essential quantifications of the global carbon sink, an interesting relationship between the measured variables used to calculate the air-sea CO₂ fluxes is overlooked. Statistically significant correlations between surface ocean pCO₂ and true wind speeds emerge when directly measured on the same platform. We explore this phenomenon and its effect on air-sea CO₂fluxes using ship, buoy, and uncrewed surface vehicle (USV) observations from the Surface Ocean CO₂ Atlas database. Preliminary results suggest that the relationship between surface ocean pCO₂ and wind speed change seasonally and regionally. In one example, observations from a USV show that in the wintertime, on the north side of the Gulf Stream, true wind speeds and surface ocean pCO₂ are significantly correlated (r = -0.59, p << 0.01), signifying strong winds align with reduced surface ocean pCO₂. Because of these correlations, the air-sea CO₂ flux is 12% greater when calculated with contemporaneous winds and pCO₂(the pCO₂ gradient across the air-sea interface) than when using their average values over the observational period. Using a paired t-Test, these means are statistically different.  This research evaluates the wind-pCO₂relationship in various locations and considers how overlooked correlations could bias quantifications of regional and global air-sea CO₂ exchange.