ESSD Earth System Science Data ESSD Earth Syst. Sci. Data 1866-3516 Copernicus Publications Göttingen, Germany 10.5194/essd-6-353-2014 A high-frequency atmospheric and seawater <i>p</i>CO<sub>2</sub> data set from 14 open-ocean sites using a moored autonomous system Sutton A. J. https://orcid.org/0000-0002-7414-7035 1 2 Sabine C. L. 2 Maenner-Jones S. 2 Lawrence-Slavas N. 2 Meinig C. 2 Feely R. A. 2 Mathis J. T. 2 Musielewicz S. 1 2 Bott R. 2 McLain P. D. 2 Fought H. J. 3 Kozyr A. 4 Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, Washington, USA Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, Washington, USA Battelle Memorial Institute, Columbus, Ohio, USA Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Department of Energy, Oak Ridge, Tennessee, USA 06 11 2014 6 2 353 366 Copyright: © 2014 A. J. Sutton et al. 2014 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://essd.copernicus.org/articles/6/353/2014/essd-6-353-2014.html The full text article is available as a PDF file from https://essd.copernicus.org/articles/6/353/2014/essd-6-353-2014.pdf

In an intensifying effort to track ocean change and distinguish between natural and anthropogenic drivers, sustained ocean time series measurements are becoming increasingly important. Advancements in the ocean carbon observation network over the last decade, such as the development and deployment of Moored Autonomous <i>p</i>CO<sub>2</sub> (MAPCO<sub>2</sub>) systems, have dramatically improved our ability to characterize ocean climate, sea–air gas exchange, and biogeochemical processes. The MAPCO<sub>2</sub> system provides high-resolution data that can measure interannual, seasonal, and sub-seasonal dynamics and constrain the impact of short-term biogeochemical variability on carbon dioxide (CO<sub>2</sub>) flux. Overall uncertainty of the MAPCO<sub>2</sub> using in situ calibrations with certified gas standards and post-deployment standard operating procedures is < 2 μatm for seawater partial pressure of CO<sub>2</sub> (<i>p</i>CO<sub>2</sub>) and < 1 μatm for air <i>p</i>CO<sub>2</sub>. The MAPCO<sub>2</sub> maintains this level of uncertainty for over 400 days of autonomous operation. MAPCO<sub>2</sub> measurements are consistent with shipboard seawater <i>p</i>CO<sub>2</sub> measurements and GLOBALVIEW-CO2 boundary layer atmospheric values. Here we provide an open-ocean MAPCO<sub>2</sub> data set including over 100 000 individual atmospheric and seawater <i>p</i>CO<sub>2</sub> measurements on 14 surface buoys from 2004 through 2011 and a description of the methods and data quality control involved. The climate-quality data provided by the MAPCO<sub>2</sub> have allowed for the establishment of open-ocean observatories to track surface ocean <i>p</i>CO<sub>2</sub> changes around the globe. Data are available at <a href="http://dx.doi.org/10.3334/CDIAC/OTG.TSM_NDP092">doi:10.3334/CDIAC/OTG.TSM_NDP092</a> and <a href="http://cdiac.ornl.gov/oceans/Moorings/ndp092"target="_blank">http://cdiac.ornl.gov/oceans/Moorings/ndp092</a>.

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