资源环境科技发展态势分析平台

A scarcity of wintertime observations of surface ocean carbon dioxide partial pressure (pCO₂) in and near the Gulf Stream creates uncertainty in the magnitude of the regional carbon sink and its controlling mechanisms. Recent observations from an Uncrewed Surface Vehicle (USV), outfitted with a payload to measure surface ocean and lower atmosphere pCO₂, revealed sharp gradients in ocean pCO₂ across the Gulf Stream. Surface ocean pCO₂ was lower by ∼50 µatm relative to the atmosphere in the subtropical mode water (STMW) formation region. This undersaturation combined with strong wintertime winds allowed for rapid ocean uptake of CO₂, averaging -11.5 mmol m^-2 day^-1 during the February 2019 USV mission. The unique timing of this mission revealed active STMW formation. The USV proved to be a useful tool for CO₂ flux quantification in the poorly observed, dynamic western boundary current environment.