Atmosphere‐ocean ozone fluxes during the TexAQS 2006, STRATUS 2006, GOMECC 2007, GasEx 2008, and AMMA 2008 cruises

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A ship‐based eddy covariance ozone flux system was deployed to investigate the magnitude and variability of ozone surface fluxes over the open ocean. The flux experiments were conducted on five cruises on board the NOAA research vesselRonald Brownduring 2006–2008. The cruises covered the Gulf of Mexico, the southern as well as northern Atlantic, the Southern Ocean, and the persistent stratus cloud region off Chile in the eastern Pacific Ocean. These experiments resulted in the first ship‐borne open‐ocean ozone flux measurement records. The median of 10 min oceanic ozone deposition velocity (vd) results from a combined ∼ 1700 h of observations ranged from 0.009 to 0.034 cm s−1. For the Gulf of Mexico cruise (Texas Air Quality Study (TexAQS)) the median vd (interquartile range) was 0.034 (0.009–0.065) cm s−1 (total number of 10 min measurement intervals, Nf = 1953). For the STRATUS cruise off the Chilean coast, the median vd was 0.009 (0.004–0.037) cm s−1 (Nf = 1336). For the cruise from the Gulf of Mexico and up the eastern U.S. coast (Gulf of Mexico and East Coast Carbon cruise (GOMECC)) a combined value of 0.018 (0.006–0.045) cm s−1 (Nf = 1784) was obtained (from 0.019 (−0.014–0.043) cm s−1, Nf = 663 in the Gulf of Mexico, and 0.018 (−0.004–0.045) cm s−1, Nf = 1121 in the North Atlantic region). The Southern Ocean Gas Exchange Experiment (GasEx) and African Monsoon Multidisciplinary Analysis (AMMA), the Southern Ocean and northeastern Atlantic cruises, respectively, resulted in median ozone vd of 0.009 (−0.005–0.026) cm s−1 (Nf = 2745) and 0.020 (−0.003–0.044) cms−1 (Nf = 1147). These directly measured ozone deposition values are at the lower end of previously reported data in the literature (0.01–0.12 cm s−1) for ocean water. Data illustrate a positive correlation (increase) of the oceanic ozone uptake rate with wind speed, albeit the behavior of the relationship appears to differ during these cruises. The encountered wide range of meteorological and ocean biogeochemical conditions is used to investigate fundamental drivers of oceanic O3 deposition and for the evaluation of a recently developed global oceanic O3 deposition modeling system.