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[1] Measurements of the d 13 C of dissolved inorganic carbon primarily during World Ocean Circulation Experiment and the Ocean Atmosphere Carbon Exchange Study cruises in the 1990s are used to determine ocean-wide changes in the d 13 C that have occurred due to uptake of anthropogenic CO 2 . This new ocean-wide d 13 C data set ($25,000 measurements) substantially improves the usefulness of d 13 C as a tracer of the anthropogenic CO 2 perturbation. The global mean d 13 C change in the surface ocean is estimated at À0.16 ± 0.02% per decade between the 1970s and 1990s with the greatest changes observed in the subtropics and the smallest changes in the polar and southern oceans. The global mean air-sea d 13 C disequilibrium in 1995 is estimated at 0.60 ± 0.10% with basin-wide disequilibrium values of 0.73, 0.63, and 0.23% for the Pacific, Atlantic, and Indian oceans, respectively. The global mean depth-integrated anthropogenic change in d 13 C between the 1970s and 1990s was estimated at À65 ± 33% m per decade. These new estimates of air-sea d 13 C disequilibrium and depth-integrated d 13 C changes yield an oceanic CO 2 uptake rate of 1.5 ± 0.6 Gt C yr À1 between 1970 and 1990 based on the atmospheric CO 2 and 13 CO 2 budget approaches of Quay et al. [1992] and Tans et al.[1993] and the dynamic method of Heimann and Maier-Reimer [1996]. Box-diffusion model simulations of the oceanic uptake of anthropogenic CO 2 and its d 13 C perturbation indicate that a CO 2 uptake rate of 1.9 ± 0.4 Gt C yr À1 (1970-1990) explains both the observed surface ocean and depth-integrated d 13 C changes. Constraining a box diffusion ocean model to match both the observed d 13 C and bomb 14 C changes yields an oceanic CO 2 uptake rate of 1.7 ± 0.2 Gt C yr À1 (1970-1990

The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEls) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in the IDP2014 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at cross-over stations. The digital data are provided in several formats, including ASCII spreadsheet, Excel spreadsheet, netCDF, and Ocean Data View collection. In addition to the actual data values the IDP2014 also contains data quality flags and 1-sigma data error values where available. Quality flags and error values are useful for data filtering. Metadata about data originators, analytical methods and original publications related to the data are linked to the data in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2014 data providing section plots and a new kind of animated 3D scenes. The basin-wide 3D scenes allow for viewing of data from many cruises at the same time, thereby providing quick overviews of large-scale tracer distributions. In addition, the 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of observed tracer plumes, as well as for making inferences about controlling processes. (C) 2015 The Authors. Published by Elsevier B.V

The 13C/12C of atmospheric methane (CH4) was measured at Point Barrow (71°N, 156°W), Olympic Peninsula (48°N, 126°W), Mauna Loa (19°N, 155°W), and Cape Grim (41°S, 144°E) between 1987 and 1989. The global average δ13CPDB from these measurements (n = 208) was −47.20 ± 0.13%o. The lowest mean annual δ13C value of‐47.61 ± 0.14‰ was measured at Point Barrow with values increasing to ‐47.03 ± 0.14‰ at Cape Grim. The seasonal cycle in the δ13C of CH4 was greatest at Point Barrow, with an amplitude of 0.5‰, and varied inversely with concentration. The isotopic fractionation during CH4 oxidation is calculated to be 0.993 ± 0.002 based on the measured CH4 concentration and δ13C values. The 14C content of atmospheric CH4, measured at monthly intervals at the Olympic Peninsula site between 1987 and 1989, is increasing at 1.4 ± 0.5 pM yr−1, primarily owing to 14CH4 release from nuclear reactors. The global average 14C content of 122 pM for CH4 implies a fossil methane source strength that is 16% of the total source. The global mean δ13C of −47.2‰, when coupled with the 14C results, implies that ∼11% of the total CH4 release rate is derived from biomass burning. These results indicate for a total CH4 source of ∼550 Tg yr−1 that natural gas release accounts for ∼90 Tg yr−1 and biomass burning yields ∼60 Tg yr−1. Preliminary analyses of the δ13C data using a three‐dimensional chemical tracer model indicate that the observed meridional gradients in the annual average δ13C and concentration of CH4 are most closely matched with a CH4 source scenario in which 11% of the CH4 is derived from biomass burning.