Twenty high-volume air samples were collected during a crossing of the North Atlantic and Canadian Archipelago in July 2005 to investigate air concentrations of fluorotelomer alcohols (FTOHs) and perfluoalkyl sulfonamido ethanols (PFASs). These commercial chemicals are widely used as surface treatments and are believed to be precursors for perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonate (PFOS) that accumulate in humans and biota, including those from remote arctic regions. The highest concentrations (sum of gas- and particle-phase) of FTOHs were for 8:2 FTOH (perfluoroctyl ethanol) (5.8-26 pg/m(3)), followed by 10:2 FTOH (perfluorodecyl ethanol) (1.9-17 pg/ m(3)) and 6:2 FTOH (perfluorohexyl ethanol) [BDL (below detection limit) to 6.0 pg/m(3)]. For the PFASs, MeFOSE (N-methyl perfluorooctane sulfonamido ethanol) was dominant and ranged from 2.6 to 31 pg/m(3); EtFOSE (N-ethyl perfluorooctane sulfonamido ethanol) ranged from BDL to 8.9 pg/m(3) and MeFOSEA (N-methyl perfluorooctane sulfonamide ethylacrylate) was BDL in all samples. Air parcel back-trajectories showed that the sampled air was largely representative of the arctic air mass. Air concentrations of target compounds were of the same order of magnitude as reported air concentrations in source regions. For instance, the mean 8:2 FTOH concentration was only a factor of about 3 lower than for three urban samples that were collected in Toronto for comparison. These findings confirm model results that predictthe efficient, long-range atmospheric transport and widespread distribution of FTOHs and related compounds in the arctic region. Mean particulate percentages for FTOHs and PFASs in the cruise samples (mean temperature, 5+/-4 degrees C) were BDL for 6:2 FTOH, 23% for 8:2 FTOH, 15% for 10:2 FTOH, 32% for MeFOSE, and 22% for EtFOSE. Further, the partitioning to particles for MeFOSE and EtFOSE was significantly correlated with inverse absolute temperature, whereas the FTOHs did not show this trend. The Toronto samples (mean temperature, -1+/-1 degree C) showed similar particulate percentages for MeFOSE and EtFOSE; however, the FTOHs were substantially less particle-bound. Although the mechanism for this partitioning is not understood, the results do indicate the need to better account for particle phase transport when modeling the atmospheric fate of these chemicals.

Abstract. The Surface Ocean CO 2 Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded f CO 2 (fugacity of carbon dioxide) products for the surface oceans. Version 2 of SOCAT is an update of the previous release (version 1) with more data (increased from 6.3 million to 10.1 million surface water f CO 2 values) and extended data coverage (from 1968-2007 to 1968-2011). The quality control criteria, while identical in both versions, have been applied more strictly in version 2 than in version 1. The SOCAT website (http://www.socat.info/) has links to quality control comments, metadata, individual data set files, and synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longerterm variation, as well as initialisation or validation of ocean carbon models and coupled climate-carbon models.

Carbon cycling in the coastal zone affects global carbon budgets and is critical for understanding the urgent issues of hypoxia, acidification, and tidal wetland loss. However, there are no regional carbon budgets spanning the three main ecosystems in coastal waters: tidal wetlands, estuaries, and shelf waters. Here we construct such a budget for eastern North America using historical data, empirical models, remote sensing algorithms, and process‐based models. Considering the net fluxes of total carbon at the domain boundaries, 59 ± 12% (± 2 standard errors) of the carbon entering is from rivers and 41 ± 12% is from the atmosphere, while 80 ± 9% of the carbon leaving is exported to the open ocean and 20 ± 9% is buried. Net lateral carbon transfers between the three main ecosystem types are comparable to fluxes at the domain boundaries. Each ecosystem type contributes substantially to exchange with the atmosphere, with CO2 uptake split evenly between tidal wetlands and shelf waters, and estuarine CO2 outgassing offsetting half of the uptake. Similarly, burial is about equal in tidal wetlands and shelf waters, while estuaries play a smaller but still substantial role. The importance of tidal wetlands and estuaries in the overall budget is remarkable given that they, respectively, make up only 2.4 and 8.9% of the study domain area. This study shows that coastal carbon budgets should explicitly include tidal wetlands, estuaries, shelf waters, and the linkages between them; ignoring any of them may produce a biased picture of coastal carbon cycling.

International audienceThe Surface Ocean CO₂ Atlas (SOCAT) is an effort by the international marine carbon research community. It aims to improve access to carbon dioxide measurements in the surface oceans by regular releases of quality controlled and fully documented synthesis and gridded fCO₂ (fugacity of carbon dioxide) products. SOCAT version 2 presented here extends the data set for the global oceans and coastal seas by four years and has 10.1 million surface water fCO₂ values from 2660 cruises between 1968 and 2011. The procedures for creating version 2 have been comparable to those for version 1. The SOCAT website (http://www.socat.info/) provides access to the individual cruise data files, as well as to the synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Scientific users can also retrieve the data as downloadable files or via Ocean Data View. Version 2 enables carbon specialists to expand their studies until 2011. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longer-term variation, as well as initialisation or validation of ocean carbon models and coupled-climate carbon models

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