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Chinese Science Bulletin

, Volume 56, Issue 24, pp 2635–2643 | Cite as

Mechanism of the Greenland-Scotland Ridge overflow variation under different atmospheric CO2 scenarios

  • Lin MuEmail author
  • Jun Song
  • LinHao Zhong
  • LanNing Wang
  • Huan Li
  • Yan Li
Open Access
Article Oceanology
  • 407 Downloads

Abstract

Baroclinic transport and the barotropic effect are two different viewpoints for understanding the mechanism of the Greenland-Scotland Ridge overflow. The mechanism of this overflow, being an important deep branch of thermohaline circulation, deserves research discussion, especially against the background of global warming. Using the newly developed ECHAM5/MPI-OM, of the Max Planck Institute for Meteorology, which is an advanced atmosphere-sea ice-ocean coupled climate model, the mechanism of the Greenland-Scotland Ridge overflow variation under different atmospheric CO2 scenarios is studied. First, a control experiment is forced by a fixed CO2 concentration of 280 ppmv, which is the pre-industrial level before 1860. Three sensitive experiments are carried out under different scenarios of increased atmospheric CO2 concentrations, which are listed in the Intergovernmental Panel on Climate Change (IPCC) assessment report (B1, A1B and A2). In the control run, more water with higher salinity intruding into the Greenland-Icelandic-Norwegian Seas results in greater barotropic transport and greater overflow because of the baroclinic effect. Therefore, the barotropic effect and baroclinic effect on the overflow are unified. Under the atmospheric CO2 scenarios, the strength of overflow across the Faro-Bank Channel is controlled by the baroclinic effect and the increase in Denmark Strait overflow is attributed to the barotropic effect.

Keywords

Greenland-Scotland Ridge overflow CO2 global warming dynamic mechanism numerical model 

References

  1. 1.
    Schmitz W J. On the interbasin-scale thermohaline circulation. Rev Geophys, 1995, 33: 151–173CrossRefGoogle Scholar
  2. 2.
    Broecker W S. The great ocean conveyor. Oceanography, 1991, 4: 79–89Google Scholar
  3. 3.
    Zhou T J, Wang S W. Preliminary evaluation on the decadal scale variability of the North Atlantic Thermohaline Circulation during 20th century (in Chinese). Clim Environ Res, 2001, 6: 294–304Google Scholar
  4. 4.
    Manabe S, Stouffer R J, Spelman M J. Transient response of a coupled ocean-atmosphere model to gradual changes of atmospheric CO2, Part I: Annual mean response. J Clim, 1991, 4: 785–818CrossRefGoogle Scholar
  5. 5.
    Swift J H, Aagaard K, Malmberg S A. The contribution of the Denmark Strait overflow to the deep North Atlantic. Deep Sea Research Part A. Oceanogr Res Papers, 1980, 27: 29–42CrossRefGoogle Scholar
  6. 6.
    Mccartney M S, Talley L D. Warm-to-cold water conversion in the northern North Atlantic Ocean. J Phys Oceanogr, 1984, 14: 922–935CrossRefGoogle Scholar
  7. 7.
    Whitehead J A. Topographic control of oceanic flows in deep passages and straits. Rev Geophys, 1998, 36: 423–440CrossRefGoogle Scholar
  8. 8.
    Mauritzen C. Production of dense overflow waters feeding the North Atlantic across the Greenland-Scotland Ridge. Part 1: Evidence for a revised circulation scheme. Deep-Sea Res, 1996, 43: 769–806CrossRefGoogle Scholar
  9. 9.
    Mauritzen C. Production of dense overflow waters feeding the North Atlantic across the Greenland-Scotland Ridge. Part 2: An inverse model. Deep-Sea Res I, 1996, 43: 807–835CrossRefGoogle Scholar
  10. 10.
    Arne B, Rolf H K, Detlef B S. The sensitivity of the Greenland-Scotland Ridge overflow to forcing changes. J Phys Oceanogr, 2003, 33: 2307–2319CrossRefGoogle Scholar
  11. 11.
    Jungclaus J H, Macrander A, Kase R. Modelling the overflows across the Greenland-Scotland Ridge. In: Dickson B, Meincke J, Rhines P. Arctic-subarctic ocean fluxes: Defining the Role of the Northern Seas in Climate. Heidelberg: Springer-Verlag Press, 2008Google Scholar
  12. 12.
    Iréne L, Peter L. Seasonal barotropic modulation of the Deep-Water Overflow through the Faroe Bank Channel. J Phys Oceanogr, 2006, 36: 2328–2339CrossRefGoogle Scholar
  13. 13.
    Roeckner E, B Uml G, Bonaventura L, et al. The atmospheric general circulation model ECHAM5: part 1: Model description. Max-Planck Institut für Meteorologie-Report, 2003. 123–349Google Scholar
  14. 14.
    Marsland S J, Haak H, Jungclaus J H, et al. The Max-Planck-Institute global ocean/sea ice model with orthogonal curvilinear coordinates. Ocean Model, 2003, 5: 91–127CrossRefGoogle Scholar
  15. 15.
    Mu L, Wu D, Chen X, et al. Analyses of the predicted changes of the global oceans under the increased greenhouse gases scenarios. Chinese Sci Bull, 2006, 51: 2651–2656CrossRefGoogle Scholar
  16. 16.
    Mu L, Wu D, Chen X, et al. Changes of the Atlantic Thermohaline Circulation under the different atmospheric CO2 scenarios in a climate model. J Chin Univ Geosci, 2006, 17: 97–102Google Scholar

Copyright information

© Science China Press and Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Lin Mu
    • 1
    • 4
    Email author
  • Jun Song
    • 1
  • LinHao Zhong
    • 2
  • LanNing Wang
    • 3
  • Huan Li
    • 1
  • Yan Li
    • 1
  1. 1.National Marine Data and Information ServiceTianjinChina
  2. 2.Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina
  3. 3.Beijing Normal UniversityBeijingChina
  4. 4.Max-Planck Institute for MeteorologyHamburgGermany

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