Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Contribution of ocean overturning circulation to tropical rainfall peak in the Northern Hemisphere

Abstract

Rainfall in the tropics is largely focused in a narrow zonal band near the Equator, known as the intertropical convergence zone. On average, substantially more rain falls just north of the Equator1. This hemispheric asymmetry in tropical rainfall has been attributed to hemispheric asymmetries in ocean temperature induced by tropical landmasses. However, the ocean meridional overturning circulation also redistributes energy, by carrying heat northwards across the Equator. Here, we use satellite observations of the Earth’s energy budget2, atmospheric reanalyses3 and global climate model simulations to study tropical rainfall using a global energetic framework. We show that the meridional overturning circulation contributes significantly to the hemispheric asymmetry in tropical rainfall by transporting heat from the Southern Hemisphere to the Northern Hemisphere, and thereby pushing the tropical rain band north. This northward shift in tropical precipitation is seen in global climate model simulations when ocean heat transport is included, regardless of whether continents are present or not. If the strength of the meridional overturning circulation is reduced in the future as a result of global warming, as has been suggested4, precipitation patterns in the tropics could change, with potential societal consequences.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Observed and modelled annual mean precipitation.
Figure 2: Observed net TOA radiation and surface energy fluxes.
Figure 3: Schematic of the role of the oceanic MOC in forcing the Northern Hemisphere maximum of tropical precipitation.

Similar content being viewed by others

References

  1. Huffman, G. J., Adler, R. F., Bolvin, D. T. & Gu, G. Improving the global precipitation record: GPCP Version 2.1. Geophys. Res. Lett. 36, L17808 (2009).

    Article  Google Scholar 

  2. Wielicki, B. A. et al. Clouds and the Earth’s radiant energy system (CERES): An Earth observing system experiment. Bull. Am. Meteorol. Soc. 77, 853–868 (1996).

    Article  Google Scholar 

  3. Dee, D. P. et al. The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Q. J. R. Meteorol. Soc. 137, 553–597 (2011).

    Article  Google Scholar 

  4. Weaver, A. J. et al. Stability of the Atlantic meridional overturning circulation: A model intercomparison. Geophys. Res. Lett. 39, L20709 (2012).

    Article  Google Scholar 

  5. Hadley, G. Concerning the cause of the general trade winds. Phil. Trans. R. Soc 29, 58–62 (1735).

    Google Scholar 

  6. Dima, I. M. & Wallace, J. M. On the seasonality of the Hadley Cell. J. Atmos. Sci. 60, 1522–1527 (2003).

    Article  Google Scholar 

  7. Frierson, D. M. W. & Hwang, Y-T. Extratropical influence on ITCZ shifts in slab ocean simulation of global warming. J. Clim. 25, 720–733 (2012).

    Article  Google Scholar 

  8. Hwang, Y-T. & Frierson, D. M. W. A new look at the double ITCZ problem: Connections to cloud bias over the Southern Ocean. Proc. Natl Acad. Sci. USA 110, 4935–4940 (2013).

    Article  Google Scholar 

  9. Hwang, Y-T., Frierson, D. M. W. & Kang, S. M. Anthropogenic sulfate aerosol and the southward shift of tropical precipitation in the 20th century. Geophys. Res. Lett. 40, 1–6 (2013).

    Article  Google Scholar 

  10. Chiang, J. C. H. & Bitz, C. M. Influence of high latitude ice cover on the marine Intertropical Convergence Zone. Clim. Dynam. 25, 477–496 (2005).

    Article  Google Scholar 

  11. Zhang, R. & Delworth, T. L. Simulated tropical response to a substantial weakening of the Atlantic thermohaline circulation. J. Clim. 18, 1853–1860 (2005).

    Article  Google Scholar 

  12. Kang, S. M., Held, I. M., Frierson, D. M. W & Zhao, M. The response of the ITCZ to extratropical thermal forcing: Idealized slab-ocean experiments with a GCM. J. Clim. 21, 3521–3532 (2008).

    Article  Google Scholar 

  13. Yoshimori, M. & Broccoli, A. J. On the link between Hadley circulation changes and radiative feedback processes. Geophys. Res. Lett. 36, L20703 (2009).

    Article  Google Scholar 

  14. Fučkar, N. S., Xie, S-P., Farneti, R., Maroon, E. A. & Frierson, D. M. W. Influence of the extratropical ocean circulation on the intertropical convergence zone in an idealized coupled general circulation model. J. Clim. 26, 4612–4629 (2013).

    Article  Google Scholar 

  15. Voigt, A., Stevens, B., Bader, J. & Mauritsen, T. The observed hemispheric symmetry in reflected shortwave irradiance. J. Clim. 26, 468–477 (2013).

    Article  Google Scholar 

  16. Marshall, J. & Speer, K. Closure of the meridional overturning circulation through Southern Ocean upwelling. Nature Geosci. 5, 171–180 (2012).

    Article  Google Scholar 

  17. Lumpkin, R. & Speer, K. Global ocean meridional overturning. J. Phys. Oceanogr. 37, 2550–2562 (2007).

    Article  Google Scholar 

  18. Marshall, J., Donohoe, A., Ferreira, D. & McGee, D. The role of the ocean circulation in setting the mean position of the ITCZ. Clim. Dyn.http://dx.doi.org/10.1007/s00382-013-1767-z (2013).

  19. Song, X. & Zhang, G. J. Convection parameterization, tropical Pacific double ITCZ, and upper ocean biases in the NCAR CCSM3. Part II: Coupled feedback and the role of ocean heat transport. J. Clim. 23, 800–812 (2010).

    Article  Google Scholar 

  20. Xie, S-P. & Philander, S. G. H. A coupled ocean-atmosphere model of relevance to the ITCZ in the eastern Pacific. Tellus 46A, 340–350 (1994).

    Article  Google Scholar 

  21. Takahashi, K. & Battisti, D. S. Processes controlling the mean tropical pacific precipitation pattern. part I: The Andes and the eastern Pacific ITCZ. J. Clim. 20, 3434–3451 (2007).

    Article  Google Scholar 

  22. DeMenocal, P. B et al. Abrupt onset and termination of the African Humid Period: Rapid climate response to gradual insolation forcing. Quat. Sci. Rev. 19, 347–361 (2000).

    Article  Google Scholar 

  23. IPCC Climate Change 2007: The Physical Science Basis (eds Solomon, S. et al.) (Cambridge Univ. Press, 2007).

  24. Trenberth, K. E. & Fasullo, J. T. An observational estimate of ocean energy divergence. J. Phys. Oceanogr. 38, 984–999 (2008).

    Article  Google Scholar 

  25. Anderson, J. L. et al. The new GFDL global atmosphere and land model AM2–LM2: Evaluation with prescribed SST simulations. J. Clim. 17, 4641–4673 (2004).

    Article  Google Scholar 

Download references

Acknowledgements

We acknowledge helpful conversations with L. Thompson, C. Bitz, K. Armour, B. Rose, I. Held, R. Pierrehumbert, D. Hartmann, J. Scheff and M. Wallace. J. Fasullo provided the ERA-Interim energy transports. We acknowledge the Program for Climate Model Diagnosis and Intercomparison and the WCRP’s Working Group on Coupled Modelling for their roles in making available the CMIP3 and CMIP5 data sets. D.M.W.F. and Y-T.H. are supported by NSF Grants AGS-0846641 and AGS-0936069, and a University of Washington Royalty Research Fund grant. N.S.F. is supported by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), by NASA through grant No. NNX07AG53G, and by NOAA through grant No. NA11NMF4320128, which sponsor research at the International Pacific Research Center. R.S. is supported by NSF award AGS-0804107. S.M.K. is supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (2013R1A1A3004589). A.D. is supported by the NOAA Climate and Global Change Fellowship, administered by the University Corporation for Atmospheric Research. E.A.M. is supported by the National Defense Science and Engineering Graduate Fellowship Program.

Author information

Authors and Affiliations

Authors

Contributions

D.M.W.F., N.S.F. and Y-T.H. designed the original diagnostics and experiments, with frequent subsequent input on diagnostic techniques and experimental design from all co-authors. Y-T.H. and D.M.W.F. analysed the observations. Y-T.H. performed experiments with the GFDL model. X.L. and D.S.B. designed experiments with the ECHAM model, and X.L. ran the ECHAM model experiments. D.M.W.F. led the writing of the paper, with substantial input from all co-authors.

Corresponding author

Correspondence to Dargan M. W. Frierson.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 874 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Frierson, D., Hwang, YT., Fučkar, N. et al. Contribution of ocean overturning circulation to tropical rainfall peak in the Northern Hemisphere. Nature Geosci 6, 940–944 (2013). https://doi.org/10.1038/ngeo1987

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ngeo1987

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing