Auxiliary material for Paper 2007GB003139 Toward a mechanistic understanding of the decadal trends in the Southern Ocean carbon sink Nicole S. Lovenduski Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA Nicolas Gruber Environmental Physics, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Zurich, Switzerland Scott C. Doney Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA Lovenduski, N. S., N. Gruber, and S. C. Doney (2008), Toward a mechanistic understanding of the decadal trends in the Southern Ocean carbon sink, Global Biogeochem. Cycles, 22, GB3016, doi:10.1029/2007GB003139. Introduction This auxiliary material contains one supplementary table and seven supplementary figures referenced in the paper. 1. 2007gb003139-ts01.txt Table S1 Estimated contributions to the natural air-sea CO2 flux trends, F', as in equation (2) (10-2 mol m-2 a-2), averaged over the Southern Ocean (<35 degrees S). Positive fluxes are to the atmosphere. Sigma is the sum of all seven terms, and F'_mod is the modeled trend in F. 2. 2007gb003139-fs01.eps Figure S1 Ten-year trends in the spatially integrated (<35 degrees S), deseasonalized natural CO2 fluxes, calculated using the sliding window method described in the text. Trends whose significance exceeds 95% are circled in red. 3. 2007gb003139-fs02.eps Figure S2 Histogram of 10-year trends in natural CO2 flux shown in Figure S1. Trends from (a) 1958-2004, and (b) 1979-2004 are shown with their mean values. 4. 2007gb003139-fs03.eps Figure S3 Trends in the spatially integrated Southern Ocean (<35 degrees S) fluxes of natural, anthropogenic, and contemporary CO2. Smoothed fluxes (12-month running mean) shown as thin lines for reference. Negative fluxes indicate ocean uptake. Natural and contemporary fluxes have been adjusted for a global -0.15 Pg C a-1 nonequilibrium flux. 5. 2007gb003139-fs04.eps Figure S4 (a) Linear trends in the air-sea flux of natural CO2 and (b) trends linearly congruent with the wind speed index from 1958-2004. Units are mol m-2 a-2, and only those trends with significance exceeding 95% are shown. Positive values indicate trends toward ocean outgassing. 6. 2007gb003139-fs05.eps Figure S5 Ten-year trends in spatially averaged (<35 degrees S) CO2 fluxes and their estimated contributions, as in equation (4). Note the differing behavior pre- and post-1979. 7. 2007gb003139-fs06.eps Figure S6 Temporal evolution of the ACC strength, defined as the mean x-direction velocity between 40 degrees S and 60 degrees S, 0 and 1000 m, and around the entire globe. Linear trend in the deseasonalized time series is shown as the heavy black line. 8. 2007gb003139-fs07.eps Figure S7 Linear trends in the (a) mixed layer depth (m a-1) and (b) export of particulate organic carbon (mol m-2 a-2) from 1979 to 2004. Positive depth trends correspond to deeper mixed layers. Particle export production is defined as the flux of particulate organic carbon across the depth of the annual-mean mixed layer.