North Atlantic Observing system

WP 4 highlights

North Atlantic CarboOcean data

Bjerknes pCO2 observing network

XX

X

X

X

Are Olsen, BCCR

X

X

Are Olsen

Ingunn Skjelvan

Abdir Omar

Johannessen/Olsen/Neill/Lauvset

X

Seasonal air-sea CO2 exchange in 2005

mmol m-2 d-1

1993-20033.6 ±0.4 µatm.yr-1

2001-2008 5.5 to 7.1 µatm.yr-1

1993-20033.6 ±0.4 µatm.yr-1

2001-2008 5.5 to 7.1 µatm.yr-1

1993-20033.6 ±0.4 µatm.yr-1

2001-2008 5.5 to 7.1 µatm.yr-1

Observed ocean fCO2 growth rates

Winter fCO2 Trends in the North Atlantic Subpolar Gyre

Corbière et al. (2007), Metzl et al., (2009)

Evolution of oceanic and atmospheric CO2

in the North Atlantic Subpolar Gyre

+3 µatm/yr

+6 µatm/yr

WarmingConvection

Corbière et al. (2007), Metzl et al., (2009)

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 moorings6oS, 10oW since 20068oN, 38oW since 2008

Advances in the quantification of air-sea CO2 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

Argos antenna

Box for electronics

Submarine part

PIRATA MOORING

JAN DEC

Two new time-series stations set up in CARBOOCEAN (at 6oS, 10oW since June 2006 and at 8oN, 38oW since April 2008) with hourly measurements of surface fCO2

Time-series stations are needed to characterize natural variability and long-term trends of CO2 in the ocean.

Atm level of CO2

Some results:

• Source of CO2 throughout

the year• Unexpected decrease in

June not well understood

yet.

Trends in the North

Equatorial counter current(Vigo group)

Thomas et al., 2008: model agrees with the trend of the data 1990s-2000s.

Thomas, H, et al., Glob Biogeo Cyc., 22, GB4027, 2008

Paper in submission to ScienceTracking the variable North Atlantic sink for atmospheric CO2

By Andrew J. Watson1, Ute Schuster1, Dorothee C. E. Bakker1, Nicholas R. Bates2, Antoine Corbière3, Melchor González-Dávila4, Tobias Friedrich5, Judith Hauck1,* Christoph Heinze6, Truls Johannessen6, Arne Körtzinger5, Nicolas Metzl3, Jon Olafsson7, Are Olsen6†, Andreas Oschlies5, X. Antonio Padin8, Benjamin Pfeil6, J. Magdalena Santana-Casiano4, Tobias Steinhoff5, Maciej Telszewski1, Aida F. Rios8, Douglas W. R. Wallace5, Rik Wanninkhof9.1. 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, France4. Universidad de Las Palmas de Gran Canaria, Faculty of Marine Science, Dept Chemistry, Las Palmas, Gran Canaria, Spain5. Leibniz Institut für Meereswissenschaften, D-24105 Kiel, Germany6. University of Bergen, Geophysical Institute & Bjerknes Centre for Climate Research, Allégaten 55, N5007, Bergen, Norway7.  Marine Research Institute and University of Iceland, Reykjavik, Iceland8. CSIC, Instituto de Investigaciones Marinas, Eduardo Cabello 6, Vigo 36208, Spain9. 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

AbstractThe oceans are a major sink for atmospheric carbon dioxide. Historically, observations have been too sparse to allow accurate tracking of changes in rates of CO2 uptake over ocean basins, so little is known about how these vary. Here we show observations indicating substantial variability in the CO2 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 CO2 sink for those ocean basins that are well-covered by shipping routes.

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.

Paper to science