1. North Atlantic Observing system WP 4 highlights

2. North Atlantic CarboOcean data

3. Bjerknes pCO 2 observing network X X X X X Are Olsen, BCCR X X Are Olsen Ingunn Skjelvan Abdir Omar Johannessen/Olsen/Neill/Lauvset X

4. Seasonal air-sea CO 2 exchange in 2005 mmol m -2 d -1

5. Winter fCO 2 Trends in the North Atlantic Subpolar Gyre Corbière et al. (2007), Metzl et al., (2009)

6. Evolution of oceanic and atmospheric CO 2 in the North Atlantic Subpolar Gyre +3 µatm/yr +6 µatm/yr Warming Convection Corbière et al. (2007), Metzl et al., (2009)

7. CARBOOCEAN: 2 VOS lines - France - French Guiana (MN Colibri) (14 voyages Feb 2006 to Mar 2009) - France - Brazil (Monte Olivia) (11 voyages July 2008 to March 2009) 2 PIRATA moorings 6 o S, 10 o W since 2006 8 o N, 38 o W since 2008 Advances in the quantification of air-sea CO 2 flux require observations in undersampled area Completed by national funding for conducting French cruises: - Africa to French Guiana - Eastern Equatorial Atlantic MN Colibri Monte Olivia

8. Argos antenna Box for electronics Submarine part PIRATA MOORING

9. JAN DEC  Two new time-series stations set up in CARBOOCEAN (at 6 o S, 10 o W since June 2006 and at 8 o N, 38 o W since April 2008) with hourly measurements of surface fCO 2 Time-series stations are needed to characterize natural variability and long-term trends of CO 2 in the ocean. Atm level of CO 2 Some results: Source of CO 2 throughout the year Unexpected decrease in June not well understood yet.

10. Trends in the North Equatorial counter current (Vigo group)

12. Thomas et al., 2008: model agrees with the trend of the data 1990s-2000s. Thomas, H, et al., Glob Biogeo Cyc., 22, GB4027, 2008

13. Paper in submission to Science Tracking the variable North Atlantic sink for atmospheric CO 2 By Andrew J. Watson 1, Ute Schuster 1, Dorothee C. E. Bakker 1, Nicholas R. Bates 2, Antoine Corbière 3, Melchor González-Dávila 4, Tobias Friedrich 5, Judith Hauck 1,* Christoph Heinze 6, Truls Johannessen 6, Arne Körtzinger 5, Nicolas Metzl 3, Jon Olafsson 7, Are Olsen 6†, Andreas Oschlies 5, X. Antonio Padin 8, Benjamin Pfeil 6, J. Magdalena Santana-Casiano 4, Tobias Steinhoff 5, Maciej Telszewski 1, Aida F. Rios 8, Douglas W. R. Wallace 5, Rik Wanninkhof 9. 1. School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK, 2. Bermuda Biological Station for Research, Ferry Reach, GE01, Bermuda, 3. LOCEAN-IPSL, CNRS, Université P et M Curie, Case 100,4 Pl Jussieu, 75252 Paris, France 4. Universidad de Las Palmas de Gran Canaria, Faculty of Marine Science, Dept Chemistry, Las Palmas, Gran Canaria, Spain 5. Leibniz Institut für Meereswissenschaften, D-24105 Kiel, Germany 6. University of Bergen, Geophysical Institute & Bjerknes Centre for Climate Research, Allégaten 55, N5007, Bergen, Norway 7. Marine Research Institute and University of Iceland, Reykjavik, Iceland 8. CSIC, Instituto de Investigaciones Marinas, Eduardo Cabello 6, Vigo 36208, Spain 9. NOAA Atlantic Oceanographic and Meteorological laboratory, Miami, Fl 33149, USA Now at: Alfred Wegener Institute for Polar and Marine Research, Postfach 12 01 61, 27515 Bremerhaven, Germany †Also at: Department of Chemistry, University of Gothenburg, 41296, Göteborg, Sweden

14. Abstract The oceans are a major sink for atmospheric carbon dioxide. Historically, observations have been too sparse to allow accurate tracking of changes in rates of CO 2 uptake over ocean basins, so little is known about how these vary. Here we show observations indicating substantial variability in the CO 2 uptake by the North Atlantic on time scales of a few years. Further, we use measurements from a co-ordinated network of instrumented commercial ships to define the annual flux into the N. Atlantic, for the year 2005, to a precision of about 10%. This approach offers the prospect of accurately monitoring the changing ocean CO 2 sink for those ocean basins that are well-covered by shipping routes.

15. Acknowledgement: We thank Seatrade Reefer Chartering, Belgium, Geest Line Ltd, UK, Royal Arctic Line, Denmark, Royal Caribbean International, USA, Eimskip Company, Iceland, and Wallenius Lines, Sweden, as well as the captains, officers, and crew of all ships for support of our projects. We acknowledge funding from the European commission under CarboOcean (project 511176, GOCE), from ICCABA CTM2005-03893/MAR and CTM2006-27116-E/MAR in Spain, The Natural Environment Research Council’s CASIX and the National Centre for Earth Observation in the UK, and from Institut National des Sciences de l'Univers and Institut Paul Emile Victor in France.

16. Paper to science