In situ measurements of atmospheric O2 and CO2 reveal an unexpected O2 signal over the tropical Atlantic Ocean

摘要: We present the first meridional transects of atmospheric O2 and CO2 over Atlantic Ocean. combine these measurements into tracer potential oxygen (APO), which is a measure oceanic contribution to variations. Our new in situ measurement system, deployed on board commercial container ship during 2015, performs as well or better than existing similar systems. The data show small short-term variability (hours days), step-change corresponding position Intertropical Convergence Zone (ITCZ), seasonal cycles that vary with latitude. In contrast from Pacific Ocean previous modeling studies, our APO no significant bulge tropics. This difference cannot be accounted for by interannual ITCZ Meridional Mode Index appears persistent feature system. Modeled using TM3 transport model does exhibit overestimates interhemispheric gradient These results indicate either there are inaccuracies flux products equatorial region, model, combination both. shipboard ongoing will reveal long-term nature outgassing more become available.