Variability of North Sea pH and CO2 in response to North Atlantic Oscillation forcing

[en] High biological activity causes a distinct seasonality of surface water pH in the North Sea, which is a strong sink for atmospheric CO 2 via an effective shelf pump. The intimate connection between the North Sea and the North Atlantic Ocean suggests that the variability of the CO 2 system of the North Atlantic Ocean may, in part, be responsible for the observed variability of pH and CO 2 in the North Sea. In this work, we demonstrate the role of the North Atlantic Oscillation (NAO), the dominant climate mode for the North Atlantic, in governing this variability. Based on three extensive observational records covering the relevant levels of the NAO index, we provide evidence that the North Sea pH and CO 2 system strongly responds to external and internal expressions of the NAO. Under positive NAO, the higher rates of in fl ow of water from the North Atlantic Ocean and the Baltic out fl ow lead to a strengthened north-south biogeochemical divide. The limited mixing between the north and south leads to a steeper gradient in pH and partial pressure of CO 2 (pCO 2 ) between the two regions in the productive period. This is exacerbated further when coinciding with higher sea surface temperature, which concentrates the net community production in the north through shallower strati fi cation. These effects can be obscured by changing properties of the constituent North Sea water masses, which are also in fl uenced by NAO. Our results highlight the importance of examining interannual trends in the North Sea CO 2 system with consideration of the NAO state

Disciplines :

Aquatic sciences & oceanology

Author, co-author :

Salt, L.A.

Thomas, H.

Prowe, A.E.F.

Borges, Alberto ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Unité d'Océanographie chimique (UOC)

Bozec, Y.

de Baar, H.J.W.

Language :

English

Title :

Variability of North Sea pH and CO2 in response to North Atlantic Oscillation forcing

Publication date :

2013

Journal title :

Journal of Geophysical Research. Biogeosciences

ISSN :

2169-8953

eISSN :

2169-8961

Publisher :

Wiley, Hoboken, United States - New Jersey

Volume :

118

Issue :

1-9

Peer reviewed :

Peer Reviewed verified by ORBi

Additional URL :

http://onlinelibrary.wiley.com/doi/10.1002/2013JG002306/abstract

Available on ORBi :

since 07 January 2014

Statistics

Number of views

64 (1 by ULiège)

Number of downloads

123 (0 by ULiège)

More statistics

Scopus citations^®

Scopus citations^®
without self-citations

OpenCitations

OpenAlex citations

Bibliography

Anderson, L. A., and, J. L. Sarmiento, (1994), Redfield ratios of remineralization determined by nutrient data analysis, Global Biogeochem. Cycles, 8, 65-80. (Pubitemid 24402983)
Artioli, Y., J. C. Blackford, M. Butenschön, J. T. Holt, S. L. Wakelin, H. Thomas, A. V. Borges, and, J. I. Allen, (2012), The carbonate system in the North Sea: Sensitivity and model validation, J. Mar. Syst., 102-104, 1-13, doi: 10.1016/j.jmarsys.2012.04.006.
Bates, N. R., (2001), Interannual variability of oceanic CO2 and biogeochemical properties in the western North Atlantic subtropical Gyre, Deep Sea Res., Part II, 48, 1507-1528. (Pubitemid 32434565)
Borges, A. V., and, M. Frankignoulle, (1999), Daily and seasonal variations of the partial pressure of CO2 in surface seawater along Belgian and southern Dutch coastal areas, J. Mar. Syst., 19, 251-266. (Pubitemid 29087670)
Borges, A. V., and, M. Frankignoulle, (2002), Distribution and air-water exchange of carbon dioxide in the Scheldt plume off the Belgian coast, Biogeochemistry, 59, 41-67. (Pubitemid 34788747)
Borges, A. V., and, N. Gypens, (2010), Carbonate chemistry in the coastal zone responds more strongly to eutrophication than to ocean acidification, Limnol. Oceanogr., 55 (1), 346-353, doi: 10.4319/lo.2010.55.1.0346.
Bozec, Y., H. Thomas, K. Elkalay, and, H. J. W. de Baar, (2005), The continental shelf pump for CO2 in the North Sea-evidence from summer observation, Mar. Chem., 93, 131-147, doi: 10.1016/j.marchem.2004.07.006. (Pubitemid 40084905)
Bozec, Y., H. Thomas, L.-S. Schiettecatte, A. V. Borges, K. Elkalay, and, H. J. W. de Baar, (2006), Assessment of the processes controlling the seasonal variations of dissolved inorganic carbon in the North Sea, Limnol. Oceanogr., 51, 2746-2762, doi: 10.4319/lo.2006.51.6.2746. (Pubitemid 44902158)
Dickson, A. G., and, F. J. Millero, (1987), A comparison of the equilibrium constants for the dissociation of carbonic acid in seawater media, Deep Sea Res., Part A, 34, 1733-1743.
DOE (2007), Guide to Best Practices for Ocean CO2 Measurements, PICES Special Publication, vol. 3, edited by, A. G. Dickson, C. L. Sabine, and, J. R. Christian, pp. 1-191, North Pacific Marine Science Organization, Sidney, Canada.
Dooley, H. D., (1974), Hypotheses concerning the circulation of the northern North Sea, J. Cons. Cons. Int. Explor. Mer, 36, 54-61.
Fofonoff, P., and, R. C. Millard Jr., (1983), Algorithms for computation of fundamental properties of seawater, UNESCO Tech. Pap. Mar. Sci., 44, 42-43.
Frankignoulle, M., and, A. V. Borges, (2001), European continental shelf as a significant sink for atmospheric carbon dioxide, Global Biogeochem. Cycles, 15, 569-576. (Pubitemid 32949200)
Gattuso, J.-P., M. Frankignoulle, and, R. Wollast, (1998), Carbon and carbonate metabolism in coastal aquatic ecosystems, Annu. Rev. Ecol. Syst., 29, 405-434. (Pubitemid 29033038)
Greatbatch, R. J., (2000), The North Atlantic Oscillation, Stochastic Environ. Res. Risk Assess., 14, 213-242, doi: 10.1007/s004770000047.
Gypens, N., G. Lacroix, C. Lancelot, and, A. V. Borges, (2011), Seasonal and inter-annual variability of air-sea CO2 fluxes and seawater carbonate chemistry in the Southern North Sea, Prog. Oceanogr., 88, 59-77, doi: 10.1016/j.pocean.2010.11.004.
Hjalmarsson, S., K. Wesslander, L. G. Anderson, A. Omstedt, M. Perttilä, and, L. Mintrop, (2008), Distribution, long-term development and mass balance calculation of total alkalinity in the Baltic Sea, Cont. Shelf Res., 28, 593-601, doi: 10.1016/j.csr.2007.11.010.
Hordoir, R., and, H. E. M. Meier, (2010), Freshwater fluxes in the Baltic Sea: A model study, J. Geophys. Res., 115, C08028, doi: 10.1029/2009JC005604.
Hurrell, J. W., (1995), Decadal trends in the North Atlantic Oscillation: Regional temperatures and precipitation, Science, 269, 676-679. (Pubitemid 26439360)
Hurrell, J. W., (2003), Climate: North Atlantic and Arctic Oscillation (NAO/AO), in Encyclopedia of Atmospheric Sciences, edited by, J. Holton, J. Pyle, and, J. Curry, pp. 439-445, Academic Press, New York.
Hurrell, J. W., and, H. van Loon, (1997), Decadal variations in climate associated with the North Atlantic Oscillation, Clim. Change, 36, 301-336, doi: 10.1023/A:1005314315270.
ICES (1983), Flushing times of the North Sea, ICES Cooperative Research Report, 123, International Council For The Exploration Of The Sea, Copenhagen.
Ionita, M., N. Rimbu, and, G. Lohmann, (2011), Decadal variability of the Elbe River streamflow, Int. J. Climatol., 31, 22-30, doi: 10.1002/joc.2054.
Kempe, S., and, K. Pegler, (1991), Sinks and sources of CO2 in coastal seas: the North Sea, Tellus, Ser. B, 43, 224-235.
Körtzinger, A., H. Thomas, B. Schneider, N. Gronau, L. Mintrop, and, J. C. Duinker, (1996), At-sea intercomparison of two newly designed underway pCO2 systems-Encouraging results, Mar. Chem., 52, 133-145.
Kühn, W., J. Pätsch, H. Thomas, A. V. Borges, L.-S. Schiettecatte, Y. Bozec, and, A. E. F. Prowe, (2010), Nitrogen and carbon cycling in the North Sea and exchange with the North Atlantic-A model study, Part II: Carbon budget and fluxes, Cont. Shelf Res., 30, 1701-1716, doi: 10.1016/j.csr.2010.07.001.
Lenhart, H. J., J. Pätsch, W. Kühn, A. Moll, and, T. Pohlmann, (2004), Investigation on the trophic state of the North Sea for three years (1994-1996) simulated with the ecosystem model ERSEM-the role of a sharp NAOI decline, Biogeosci. Discuss., 1, 725-754, doi: 10.5194/bgd-1-725-2004.
Levine, N. M., S. C. Doney, I. Lima, R. Wanninkhof, N. R. Bates, and, R. A. Feely, (2011), The impact of the North Atlantic Oscillation on the uptake and accumulation of anthropogenic CO2 by North Atlantic Ocean mode waters, Global Biogeochem. Cycles, 25, GB3022, doi: 10.1029/2010GB003892.
Lorkowski, I., J. Pätsch, A. Moll, and, W. Kühn, (2012), Interannual variability of carbon fluxes in the North Sea from 1970 to 2006-Competing effects of abiotic and biotic drivers on the gas-exchange of CO2, Estuarine Coastal Shelf Sci., 100, 38-57, doi: 10.1016/j.ecss.2011.11.037.
McKinley, G. A., A. R. Fay, T. Takahashi, and, N. Metzl, (2011), Convergence of atmospheric and North Atlantic carbon dioxide trends on multidecadal timescales, Nat. Geosci., 4, 606-610, doi: 10.1038/NGEO1193.
Mehrbach, C., C. H. Culberson, J. E. Hawley, and, R. M. Pytkowicz, (1973), Measurement of the apparent dissociation constants of carbonic acid in seawater at atmospheric pressure, Limnol. Oceanogr., 18, 897-907.
Omar, A. M., A. Olsen, T. Johannessen, M. Hoppema, H. Thomas, and, A. V. Borges, (2010), Spatiotemporal variations of fCO2 in the North Sea, Ocean Sci., 6, 77-89, doi: 10.5194/os-6-77-2010.
Otto, L., J. T. F. Zimmerman, G. K. Furnes, M. Mork, R. Saetre, and, G. Becker, (1990), Review of the physical oceanography of the North Sea, Neth. J. Sea Res., 26 (2-4), 161-238.
Pätsch, J., and, W. Kühn, (2008), Nitrogen and carbon cycling in the North Sea and exchange with the North Atlantic-a model study. Part I. Nitrogen budget and fluxes, Cont. Shelf Res., 28, 767-787, doi: 10.1016/j.csr.2007.12.013.
Pérez, F. F., M. Vázquez-Rodríguez, H. Mercier, A. Velo, P. Lherminier, and, A. F. Ríos, (2010), Trends of anthropogenic CO2 storage in North Atlantic water masses, Biogeosciences, 7, 1789-1807, doi: 10.5194/bg-7-1789-2010.
Prowe, A. E. F., H. Thomas, J. Pätsch, W. Kühn, Y. Bozec, L.-S. Schiettecatte, A. V. Borges, and, H. J. W. de Baar, (2009), Mechanisms controlling the air-sea CO2 flux in the North Sea, Cont. Shelf Res., 29, 1801-1808, doi: 10.1016/j.csr.2009.06.003.
Santana-Casiano, J. M., M. González-Dávila, M.-J. Rueda, O. Llinás, and, E.-F. González-Dávila, (2007), The interannual variability of oceanic CO2 parameters in the northeast Atlantic subtropical gyre at the ESTOC site, Global Biogeochem. Cycles, 21, GB1015, doi: 10.1029/2006GB002788.
Schiettecatte, L.-S., F. Gazeau, C. Van der Zee, N. Brion, and, A. V. Borges, (2006), Time series of the partial pressure of carbon dioxide (2001-2004) and preliminary inorganic carbon budget in the Scheldt plume (Belgian coast waters), Geochem. Geophys. Geosyst. 7, Q06009, doi: 10.1029/2005GC001161.
Schiettecatte, L.-S., H. Thomas, Y. Bozec, and, A. V. Borges, (2007), High temporal coverage of carbon dioxide measurements in the Southern Bight of the North Sea, Mar. Chem., 106, 161-173, doi: 10.1016/j.marchem.2007.01.001. (Pubitemid 47211586)
Schuster, U., and, A. J. Watson, (2007), A variable and decreasing sink for atmospheric CO2 in the North Atlantic, J. Geophys. Res., 112, C11006, doi: 10.1029/2006JC003941.
Schuster, U., A. J. Watson, N. R. Bates, A. Corbiere, M. Gonzalez-Davila, N. Metzl, D. Pierrot, and, M. Santana-Casiano, (2009), Trends in North Atlantic sea-surface fCO2 from 1990 to 2006, Deep Sea Res., Part II, 56 (8-10), 620-629, doi: 10.1016/j.dsr2.2008.12.011.
Shadwick, E., H. Thomas, Y. Gratton, D. Leong, S. A. Moore, T. Papakyriakou, and, A. E. F. Prowe, (2011), Export of Pacific carbon through the Arctic Archipelago to the North Atlantic, Cont. Shelf Res., 31, 806-816, doi: 10.1016/j.csr.2011.01.014.
Takahashi, T., J. Olafsson, J. G. Goddard, D. W. Chipman, and, S. C. Sutherland, (1993), Seasonal-variation of CO2 and nutrients in the high-latitude surface oceans-a comparative study, Global Biogeochem. Cycles, 7, 843-878. (Pubitemid 24430526)
Thomas, H., and, B. Schneider, (1999), The seasonal cycle of carbon dioxide in Baltic Sea surface waters, J. Mar. Syst., 22, 53-67. (Pubitemid 29437575)
Thomas, H., Y. Bozec, K. Elkalay, and, H. J. W. de Baar, (2004), Enhanced open ocean storage of CO2 from shelf sea pumping, Science, 304 (5673), 1005-1008, doi: 10.1126/science.1095491. (Pubitemid 38638097)
Thomas, H., Y. Bozec, H. J. W. de Baar, K. Elkalay, M. Frankignoulle, L.-S. Schiettecatte, G. Kattner, and, A. V. Borges, (2005a), The carbon budget of the North Sea, Biogeosciences, 2, 87-96, doi: 10.5194/bg-2-87-2005. (Pubitemid 40960819)
Thomas, H., Y. Bozec, K. Elkalay, H. J. W. de Baar, A. V. Borges, and, L.-S. Schiettecatte, (2005b), Controls of the surface water partial pressure of CO2 in the North Sea, Biogeosciences, 2, 323-334, doi: 10.5194/bg-2-323-2005. (Pubitemid 43088466)
Thomas, H., et al. (2007), Rapid decline of the CO2 buffering capacity in the North Sea and implications for the North Atlantic Ocean, Global Biogeochem. Cycles, 21, GB4001, doi: 10.1029/2006GB002825.
Thomas, H., A. E. F. Prowe, I. D. Lima, S. C. Doney, R. Wanninkhof, R. J. Greatbatch, U. Schuster, and, A. Corbière, (2008a), Changes in the North Atlantic Oscillation influence CO2 uptake in the North Atlantic over the past 2 decades, Global Biogeochem. Cycles, 22, GB4027, doi: 10.1029/2007GB003167.
Thomas, H., D. Unger, J. Zhang, K.-K. Liu, and, E. H. Shadwick, (2008b), Biogeochemical cycling, in Watersheds, Bays and Bounded Seas, SCOPE No. 70, edited by, E. Urban, et al., pp. 169-190, Island Press, Washington, D. C.
Thomas, H., L.-S. Schiettecatte, K. Suykens, Y. J. M. Koné, E. H. Shadwick, A. E. F. Prowe, Y. Bozec, H. J. W. de Baar, and, A. V. Borges, (2009), Enhanced ocean carbon storage from anaerobic alkalinity generation in coastal sediments, Biogeosciences, 6, 267-274, doi: 10.5194/bg-6-267-2009.
Tsunogai, S., S. Watanabe, and, T. Sato, (1999), Is there a "continental shelf pump" for the absorption of atmospheric CO 2?, Tellus, Ser. B, 51, 701-712. (Pubitemid 29532444)
Wakelin, S. L., J. T. Holt, J. C. Blackford, J. I. Allen, M. Butenschön, and, Y. Artioli, (2012), Modelling the carbon fluxes of the northwest European continental shelf: Validation and budgets, J. Geophys. Res., 117, C05020, doi: 10.1029/2011JC007402.
Watson, A. J., et al. (2009), Tracking the variable North Atlantic sink for atmospheric CO2, Science, 326 (5958), 1391-1393, doi: 10.1126/science.1177394.
Winther, N. G., and, J. A. Johannessen, (2006), North Sea circulation: Atlantic inflow and its destination, J. Geophys. Res., 111, C12018, doi: 10.1029/2005JC003310.
Wollast, R., (1998), Evaluation and comparison of the global carbon cycle in the coastal zone and in the open ocean, in The Global Coastal Ocean, edited by, K. H. Brink, and, A. R. Robinson, pp. 213-252, John Wiley & Sons, New York.