Abstract：
Rates of seawater acidification and rise of partial pressure of CO2 (pCO2) at ocean margins are highly uncertain. In this study, nine years of time-series data sampled during 2010-2018 along Kuroshio Current near the East China Sea (ECS) were investigated. We found trends of surface seawater pCO2 at 3.70 ± 0.57 μatm year-1 and pH at -0.0033 ± 0.0009 unityear-1, both of which were significantly greater than those reported from other oceanic time series. Mechanistic analysis showed that seawater warming caused rapid rates of pCO2 increase and acidification under sustained DIC increase. The faster pCO2 growth relative to the atmosphere resulted in the CO2 uptake through the air-sea exchange declining by ~50 % (~-0.8 to -0.4 mol C m-2 year-1) over the study period. Our results imply that rapidly warming boundary currents could potentially present an elevated pCO2 trend, leading to a gradual reduction and eventual loss of oceanic CO2 uptake under climate change.
摘要：
海水酸化的速率和海洋边缘的CO2分压（pCO2）的升高是高度不确定的。在这项研究中,调查了2010-2018年沿东海（ECS）附近的黑潮洋流采样的9年时间序列数据。我们发现表层海水pCO2的趋势为3.70±0.57μatmyear-1，pH为-0.0033±0.0009unityear-1，两者均显着大于其他海洋时间序列报道的趋势。机理分析表明，在持续的DIC增加下，海水变暖导致pCO2增加和酸化速率较快。在研究期间，相对于大气更快的pCO2增长导致通过海气交换吸收的CO2下降了约50％（〜-0.8至-0.4molCm-2year-1）。我们的结果表明，快速变暖的边界电流可能会呈现pCO2升高的趋势，导致气候变化下海洋二氧化碳吸收的逐渐减少和最终损失。
