Response to Comments on "Saturation of the Southern Ocean CO2 Sink Due to Recent Climate Change"
Corinne Le Quéré1,2*,
Christian Rödenbeck3,
Erik T. Buitenhuis1,
Thomas J. Conway4,
Ray Langenfelds5,
Antony Gomez6,
Casper Labuschagne7,
Michel Ramonet8,
Takakiyo Nakazawa9,
Nicolas Metzl10,
Nathan P. Gillett11 and
Martin Heimann3
1 School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
2 British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK.
3 Max Planck Institut für Biogeochemie, Postfach 100164, D-07701 Jena, Germany.
4 National Oceanic and Atmospheric Administration, Earth System Research Laboratory, 325 Broadway, Boulder, CO 80305, USA.
5 Commonwealth Scientific and Industrial Research Organisation, Marine and Atmospheric Research, PMB1, Aspendale, Victoria 3195, Australia.
6 National Institute for Water and Atmospheric Research, Post Office Box 14-901, Wellington, New Zealand.
7 South African Weather Service, Post Office Box 320, Stellenbosch 7599, South Africa.
8 Laboratoire des Sciences du Climat et de l'Environnement/Institut Pierre Simon Laplace (LSCE/IPSL), Gif-sur-Yvettes, Cedex 91191, France.
9 Center for Atmospheric and Oceanic Studies, Tohoku University, Sendai 980-8578, Japan.
10 Laboratoire d'Océanographie et du Climat: Expérimentation et Approches Numériques (LOCEAN/IPSL), Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Paris, France.
11 Climatic Research Unit, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
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Fig. 1. World map showing the location of the 11 stations used in the standard inversion in (1) (blue triangles) and the five stations used in (2) (red circles). Other stations discussed in the text are shown in small blue dots.
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Fig. 2. Trends in sea-air CO2 flux in the Southern Ocean from inversions with increasing number of stations (9). The trends used in (1) are shown in black. These include the most complete station network, excluding stations with large gaps in the data. Trends for inversions using 12 stations or fewer are computed over the 1981 to 2004 time period. Trends using 16 or 17 stations are computed over the 1986 to 2004 time period. As explained in the text, trends estimated with fewer than 11 stations (hatched bars) are strongly dependent on the station network and thus are not reliable estimates. Fluxes are integrated over 45°S to 90°S.
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Fig. 3. Comparison between observed and modeled sea surface temperature anomaly in the Southern Ocean. The modeled estimate is from (1)(black line). The observed estimates are from (14) (dotted blue line) based on in-situ temperature observations and from (15) (full blue line) updated to 2006 based on satellite observations.
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Fig. 4. Schematic view of the impact of increased winds on the Southern Ocean CO2 sink. The three panels represent conditions in the present ocean (left), under very high atmospheric CO2 (middle), and more than 100 years after the CO2 emissions cease (right). C is the concentration of carbon in the surface and deep oceans in units of µmol kg–1, whereas  C' is the increase in carbon content of the ocean from human CO2 emissions. The observed concentrations are from (15), south of 45°S.
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