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Climate Dynamics

, Volume 43, Issue 11, pp 2931–2941 | Cite as

Weakening AMOC connects Equatorial Atlantic and Pacific interannual variability

  • Lea SvendsenEmail author
  • Nils Gunnar Kvamstø
  • Noel Keenlyside
Article

Abstract

Observations indicate that since the 1970s Equatorial Atlantic sea surface temperature (SST) variations in boreal summer tend to modulate El Niño in the following seasons, indicating that the Atlantic Ocean can have importance for predicting the El Niño–Southern Oscillation (ENSO). The cause of the change in the recent decades remains unknown. Here we show that in the Bergen Climate Model (BCM), a freshwater forced weakening of the Atlantic meridional overturning circulation (AMOC) results in a strengthening of the relation between the Atlantic and the Pacific similar to that observed since the 1970s. During the weakening AMOC phase, SST and precipitation increase in the central Equatorial Atlantic, while the mean state of the Pacific does not change significantly. In the Equatorial Atlantic the SST variability has also increased, with a peak in variability in boreal summer. In addition, the characteristic timescales of ENSO variability is shifted towards higher frequencies. The BCM version used here is flux-adjusted, and hence Atlantic variability is realistic in contrast to in many other models. These results indicate that in the BCM a weakening AMOC can change the mean background state of the Tropical Atlantic surface conditions, enhancing Equatorial Atlantic variability, and resulting in a stronger relationship between the Tropical Atlantic and Pacific Oceans. This in turn alters the variability in the Pacific.

Keywords

El Niño–Southern Oscillation Atlantic Zonal Mode Atlantic Niño Atlantic Meridional Overturning Circulation Bergen Climate Model Interannual variability 

Notes

Acknowledgments

We thank Tarjei Breiteig, Helge Drange, Stefan Sobolowski, Tore Furevik and Jin-Yi Yu for valuable discussions and input, and Ingo Bethke for providing support with BCM data. We also thank two anonymous reviewers for constructive suggestions and comments. This study has been supported by the Research Council of Norway through the IndiaClim project, as well as by the EU FP7 SUMO (No. 266722) and STEPS (PCIG10-GA-2011-304243) projects.

References

  1. Bjerknes J (1969) Atmospheric teleconnections from equatorial Pacific. Mon Weather Rev 97(3):163–172CrossRefGoogle Scholar
  2. Bleck R, Rooth C, Hu D, Smith L (1992) Salinity-driven thermocline transients in a 14wind-forced and thermohaline-forced isopycnic coordinate model of the North Atlantic. J Phys Oceanogr 22(12):1486–1505CrossRefGoogle Scholar
  3. Breiteig T (2009) The influence of the ocean and the stratosphere on climate persistence in the North Atlantic region. University of Bergen, DissertationGoogle Scholar
  4. Broecker W, Peteet D, Rind D (1985) Does the ocean-atmosphere have more than one stable mode of operation. Nature 315:21–25CrossRefGoogle Scholar
  5. Brönnimann S (2007) Impact of El Nino Southern Oscillation on European climate. Rev Geophys 45(2):RG3003. doi: 10.1029/2006RG000199 Google Scholar
  6. Chang P, Fang Y, Saravanan R, Ji L, Seidel H (2006) The cause of the fragile relationship between the Pacific El Nino and the Atlantic Nino. Nature 443(7109):324–328CrossRefGoogle Scholar
  7. Davey M, Huddleston M, Sperber K, Braconnot P, Bryan F, Chen D, Colman R, Cooper C, Cubasch U, Delecluse P (2002) Stoic: a study of coupled model climatology and variability in tropical ocean regions. Clim Dyn 18(5):403–420CrossRefGoogle Scholar
  8. Deque M, Dreveton C, Braun A, Cariolle D (1994) The ARPEGE/IFS atmosphere model—a contribution to the French community climate modeling. Clim Dyn 10(4–5):249–266Google Scholar
  9. Ding H, Keenlyside NS, Latif M (2010) Equatorial Atlantic interannual variability: the role of heat content. J Geophys Res 115:C09020. doi: 10.1029/2010JC006304
  10. Ding H, Keenlyside NS, Latif M (2012) Impact of the equatorial Atlantic on the El Niño Southern Oscillation. Clim Dyn 38:1965–1972CrossRefGoogle Scholar
  11. Dommenget D, Semenov V, Latif M (2006) Impacts of the tropical Indian and Atlantic Oceans on ENSO. Geophys Res Lett 33(11):L11,701. doi: 10.1029/2006GL025871 CrossRefGoogle Scholar
  12. Dong B, Sutton RT (2002) Adjustment of the coupled ocean-atmosphere system to a sudden change in the Thermohaline Circulation. Geophys Res Lett 29(15):1728. doi: 10.1029/2002GL015229 CrossRefGoogle Scholar
  13. Dong B, Sutton RT (2007) Enhancement of ENSO variability by a weakened Atlantic thermohaline circulation in a coupled GCM. J Clim 20(19):4920–4939CrossRefGoogle Scholar
  14. Enfield D, Mayer D (1997) Tropical Atlantic sea surface temperature variability and its relation to El Niño–Southern Oscillation. J Geophys Res 102(C1):929–945. doi: 10.1029/96JC03296 CrossRefGoogle Scholar
  15. Frauen C, Dommenget D (2012) Influences of the tropical Indian and Atlantic Oceans on the predictability of ENSO. Geophys Res Lett 39(2):L02,706. doi: 10.1029/2011GL050520 CrossRefGoogle Scholar
  16. Furevik T, Bentsen M, Drange H, Kindem IKT, Kvamstø NG, Sorteberg A (2003) Description and evaluation of the Bergen climate model: ARPEGE coupled with MICOM. Clim Dyn 21(1):27–51CrossRefGoogle Scholar
  17. Ganopolski A, Rahmstorf S (2001) Rapid changes of glacial climate simulated in a coupled climate mode. Nature 409:153–158CrossRefGoogle Scholar
  18. Ham Y-G, Kug J-S, Park J-Y, Jin F-F (2013) Sea surface temperature in the north tropical Atlantic as a trigger for El Niño/Southern Oscillation events. Nat Geosci. doi: 10.1038/ngeo1686
  19. Hoskins BJ, Karoly DJ (1981) The steady linear response of a spherical atmosphere to thermal and orographic forcing. J Atmos Sci 38:1179–1196CrossRefGoogle Scholar
  20. Jansen MF, Dommenget D, Keenlyside N (2009) Tropical atmosphere-ocean interactions in a conceptual framework. J Clim 22(3):550–567CrossRefGoogle Scholar
  21. Kao H-Y, Yu J-Y (2009) Contrasting eastern-Pacific and central-Pacific types of ENSO. J Clim 22(3):615–632CrossRefGoogle Scholar
  22. Keenlyside N, Latif M (2007) Understanding equatorial Atlantic interannual variability. J Clim 20(1):131–142CrossRefGoogle Scholar
  23. Keenlyside N, Ding H, Latif M (2013) Potential of Equatorial Atlantic Variability to Enhance El Niño Prediction. Geophys Res Lett 40:2278–2283CrossRefGoogle Scholar
  24. Kuhlbrodt T, Griesel A, Montoya M, Levermann A, Hofmann M, Rahmstorf S (2007) On the driving processes of the Atlantic meridional overturning circulation. Rev Geophys 45(1):RG2001. doi: 10.1029/2004RG000166 Google Scholar
  25. Latif M, Grötzner A (2000) The equatorial Atlantic oscillation and its response to ENSO. Clim Dyn 16(2–3):213–218CrossRefGoogle Scholar
  26. Latif M, Keenlyside NS (2009) El Niño/Southern Oscillation response to global warming. Proc Natl Acad Sci USA 106(49):20578–20583CrossRefGoogle Scholar
  27. Latif M, Sperber K, Arblaster J, Braconnot P, Chen D, Colman A, Cubasch U, Cooper C, Delecluse P, Dewitt D, Fairhead L, Flato G, Hogan T, Ji M, Kimoto M, Kitoh A, Knutson T, Le Treut H, Li T, Manabe S, Manabe S, Marti O, Mechoso C, Meehl G, Power S, Roeckner E, Sirven J, Terray L, Vintzileos A, Voss R, Wang B, Washington W, Yoshikawa I, Yu J, Zebiak S (2001) ENSIP:the El Niño simulation intercomparison project. Clim Dyn 18:255–276CrossRefGoogle Scholar
  28. Manabe S, Stouffer RJ (1994) Multiple-century response of a coupled ocean- atmosphere model to an increase of atmospheric carbon dioxcide. J Clim 7:5–23CrossRefGoogle Scholar
  29. Manabe S, Stouffer RJ (1997) Coupled ocean-atmosphere model response to freshwater input: comparison to Younger Dryas event. Paleoceanography 12:321–336CrossRefGoogle Scholar
  30. Otterå OH, Drange H, Bentsen M, Kvamstø NG, Jiang D (2003) The sensitivity of the present-day Atlantic meridional overturning circulation to freshwater forcing. Geophys Res Lett 30(17):1898. doi: 10.1029/2003GL017578 CrossRefGoogle Scholar
  31. Otterå OH, Drange H, Bentsen M, Kvamstø NG, Jiang D (2004) Transient response of the Atlantic meridional overturning circulation to enhanced freshwater input to the Nordic Seas-Arctic Ocean in the Bergen climate model. Tellus A 56(4):342–361. doi: 10.1111/j.1600-0870.2004.00063.x CrossRefGoogle Scholar
  32. Philander S (1990) El Niño, La Niña, and the southern Oscillation. Academic Press, San DiegoGoogle Scholar
  33. Räisänen J (2001) CO2-induced climate change in CMIP2 experiments. SWECLIM Newsl 11:23–28Google Scholar
  34. Rayner NA, DE Parker, Horton EB, Folland CK, Alexander LV, Rowell DP, Kent EC, Kaplan A (2003) Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J Geophys Res 108(D14):4407. doi: 10.1029/2002JD002670 CrossRefGoogle Scholar
  35. Richter I, Xie S-P (2008) On the origin of equatorial Atlantic biases in coupled general circulation models. Clim Dyn 31(5):587–598CrossRefGoogle Scholar
  36. Rind D, deMenocal P, Russell G, Sheth S, Collins D, Schmidt G, Teller J (2001) Effects of glacial meltwater in the GISS coupled atmosphere-ocean model: Part I. North Atlantic Deep Water response. J Geophys Res 16:27335–27354CrossRefGoogle Scholar
  37. Rodriguez-Fonseca B, Polo I, Garcia-Serrano J, Losada T, Mohino E, Mechoso CR, Kucharski F (2009) Are Atlantic Niños enhancing Pacific ENSO events in recent decades? Geophys Res Lett 36(20):L20,705. doi: 10.1029/2009GL040048 CrossRefGoogle Scholar
  38. Schiller A, Mikolajewicz U, Voss R (1997) The stability of the North Atlantic thermohaline circulation in a coupled ocean-atmosphere general circulation model. Clim Dyn 13(5):325–347CrossRefGoogle Scholar
  39. Schmittner A, Latif M, Schneider B (2005) Model projections of the North Atlantic thermohaline circulation for the 21st century assessed by observations. Geophys Res Lett 32(23):L23,710. doi: 10.1029/2005GL024368 CrossRefGoogle Scholar
  40. Simonsen K (1996) Heat budgets and freshwater forcing of the Nordic Seas and the Arctic Ocean. Dissertation, Nansen Environmental and Remote Sensing Center, BergenGoogle Scholar
  41. Stouffer R, Yin J, Gregory J, Dixon K, Spelman M, Hurlin W, Weaver A, Eby M, Flato G, Hasumi H, Hu A, Jungclaus J, Kamenkovich I, Levermann A, Montoya M, Murakami S, Nawrath S, Oka A, Peltier W, Robitaille D, Sokolov A, Vettoretti G, Weber S (2006) Investigating the causes of the response of the thermohaline circulation to past and future climate changes. J Clim 19(8):1365–1387CrossRefGoogle Scholar
  42. Sutton RT, Hodson DLR (2007) Climate response to basin-scale warming and cooling of the North Atlantic Ocean. J Clim 20(5):891–907CrossRefGoogle Scholar
  43. Terray L, Thual O, Belamari S, Déque M, Dandin P, Delecluse P, Levy C (1995) Climatology and interannual variability simulated by the ARPEGE-OPA coupled model. Clim Dyn 11:487–505CrossRefGoogle Scholar
  44. Terray L, Valke S, Piacentini A (1998) OASIS 2.2 user’s guide and reference manual. Technical report, CERFACS, Toulouse, FranceGoogle Scholar
  45. Timmermann A, An S, Krebs U, Goosse H (2005) ENSO suppression due to weakening of the North Atlantic thermohaline circulation. J Clim 18(16):3122–3139CrossRefGoogle Scholar
  46. Tokinaga H, Xie S-P (2011) Weakening of the equatorial Atlantic cold tongue over the past six decades. Nat Geosci 4(4):222–226CrossRefGoogle Scholar
  47. Venzke S, Latif M, Villwock A (2000) The coupled GCM ECHO-2. Part II: Indian Ocean response to ENSO. J Clim 13:1371–1383CrossRefGoogle Scholar
  48. Wallace JM, Gutzler DS (1980) Teleconnections in the geopotential height field during the Northern Hemisphere winter. Mon Weather Rev 109:784–812CrossRefGoogle Scholar
  49. Wang C (2006) An overlooked feature of tropical climate: inter-Pacific-Atlantic variability. Geophys Res Lett 33(12):L12,702. doi: 10.1029/2006GL026324 CrossRefGoogle Scholar
  50. Wen C, Ping C, Saravanan R (2010) Effect of Atlantic meridional overturning circulation changes on tropical Atlantic sea surface temperature variability: a 2½-layer reduced-gravity ocean model study. J Clim 23:312–332CrossRefGoogle Scholar
  51. Wittenberg AT (2009) Are historical records sufficient to constrain ENSO simulations? Geophys Res Lett 36(12):L12,702. doi: 10.1029/2009GL038710 CrossRefGoogle Scholar
  52. Yeh S-W, Kug J-S, Dewitte B, Kwon M-H, Kirtman BP, Jin F-F (2009) El Niño in a changing climate. Nature 461(7263):511–514CrossRefGoogle Scholar
  53. Zebiak SE (1993) Air-sea interaction in the equatorial Atlantic region. J Clim 6(8):1567–1568CrossRefGoogle Scholar
  54. Zhang R, Delworth TL (2005) Simulated tropical response to a substantial weakening of the Atlantic thermohaline circulation. J Clim 18(12):1853–1860CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Lea Svendsen
    • 1
    • 3
    Email author
  • Nils Gunnar Kvamstø
    • 2
    • 3
  • Noel Keenlyside
    • 2
    • 3
  1. 1.Nansen Environmental and Remote Sensing CenterBergenNorway
  2. 2.Geophysical InstituteUniversity of BergenBergenNorway
  3. 3.Bjerknes Centre for Climate ResearchUniversity of BergenBergenNorway

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