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Hemispheric climate shifts driven by anthropogenic aerosol–cloud interactions

Abstract

The contrasting rainfall between the wet tropics and the dry subtropics largely determines the climate of the tropical zones. A southward shift of these rain belts has been observed throughout the latter half of the twentieth century, with profound societal consequences. Although such large-scale shifts in rainfall have been linked to interhemispheric temperature gradients from anthropogenic aerosols, a complete understanding of this mechanism has been hindered by the lack of explicit information on aerosol radiative effects. Here we quantify the relative contributions of radiative forcing from anthropogenic aerosols to the interhemispheric asymmetry in temperature and precipitation change for climate change simulations. We show that in model simulations the vast majority of the precipitation shift does not result from aerosols directly through their absorption and scattering of radiation, but rather indirectly through their modification of cloud radiative properties. Models with larger cloud responses to aerosol forcing are found to better reproduce the observed interhemispheric temperature changes and tropical rain belt shifts over the twentieth century, suggesting that aerosol–cloud interactions will play a key role in determining future interhemispheric shifts in climate.

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Figure 1: Response of precipitation and surface air temperature to increased anthropogenic aerosols in anthropogenic-aerosol-only (historicalAA) simulations.
Figure 2: Comparisons of the interhemispheric climate asymmetry with aerosol forcing from coupled and fixed-SST models.
Figure 3: Response of precipitation and surface air temperature to aerosol and greenhouse gas forcings.
Figure 4: Comparisons of the total aerosol forcing and its components with the interhemispheric climate asymmetry in multi-forcing simulations.
Figure 5: Interhemispheric asymmetry in temperature change.

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References

  1. Hwang, Y.-T., Frierson, D. M. W. & Kang, S. M. Anthropogenic sulfate aerosol and the southward shift of tropical precipitation in the late 20th century. Geophys. Res. Lett. 40, 2845–2850 (2013).

    Article  Google Scholar 

  2. Allen, R. J., Evan, A. T. & Booth, B. B. B. Interhemispheric aerosol radiative forcing and tropical precipitation shifts during the late twentieth century. J. Clim. 28, 8219–8246 (2015).

    Article  Google Scholar 

  3. Rotstayn, L. D. & Lohmann, U. Tropical rainfall trends and the indirect aerosol effect. J. Clim. 15, 2103–2116 (2002).

    Article  Google Scholar 

  4. Wang, C. Anthropogenic aerosols and the distribution of past large-scale precipitation change. Geophys. Res. Lett. 42, 10876–10884 (2015).

    Google Scholar 

  5. Nicholson, S. E. An overview of African rainfall fluctuations of the last decade. J. Clim. 6, 1463–1466 (1993).

    Article  Google Scholar 

  6. Folland, C. K., Palmer, T. N. & Parker, D. E. Sahel rainfall and worldwide sea temperatures, 1901–85. Nature 320, 602–607 (1986).

    Article  Google Scholar 

  7. Giannini, A., Saravanan, R. & Chang, P. Oceanic forcing of Sahel rainfall on interannual to interdecadal time scales. Science 302, 1027–1030 (2003).

    Article  Google Scholar 

  8. Zhang, R. & Delworth, T. L. Impact of Atlantic multidecadal oscillations on India/Sahel rainfall and Atlantic hurricanes. Geophys. Res. Lett. 33, L17712 (2006).

    Article  Google Scholar 

  9. 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 

  10. Haywood, J. M., Jones, A., Bellouin, N. & Stephenson, D. Asymmetric forcing from stratospheric aerosols impacts Sahelian rainfall. Nat. Clim. Change 3, 660–665 (2013).

    Article  Google Scholar 

  11. Ceppi, P. et al. The relationship between the ITCZ and the Southern Hemisphere eddy-driven jet. J. Geophys. Res. 118, 5136–5146 (2013).

    Article  Google Scholar 

  12. Frierson, D. M. W. et al. Contribution of ocean overturning circulation to tropical rainfall peak in the Northern Hemisphere. Nat. Geosci. 6, 940–944 (2013).

    Article  Google Scholar 

  13. Loeb, N. G. et al. Observational constraints on atmospheric and oceanic cross-equatorial heat transports: revisiting the precipitation asymmetry problem in climate models. Clim. Dynam. 46, 3239–3257 (2016).

    Article  Google Scholar 

  14. Twomey, S. The influence of pollution on the shortwave albedo of clouds. J. Atmos. Sci. 34, 1149–1152 (1977).

    Article  Google Scholar 

  15. Albrecht, B. A. Aerosols, cloud microphysics, and fractional cloudiness. Science 245, 1227–1230 (1989).

    Article  Google Scholar 

  16. Myhre, G. et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 659–740 (IPCC, Cambridge Univ. Press, 2013).

    Google Scholar 

  17. Boucher, O. et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 571–657 (IPCC, Cambridge Univ. Press, 2013).

    Google Scholar 

  18. Forster, P. M. et al. Evaluating adjusted forcing and model spread for historical and future scenarios in the CMIP5 generation of climate models. J. Geophys. Res. 118, 1139–1150 (2013).

    Google Scholar 

  19. Hegerl, G. C. et al. Challenges in quantifying changes in the global water cycle. Bull. Am. Meteorol. Soc. 96, 1097–1115 (2015).

    Article  Google Scholar 

  20. Wilcox, L. J., Highwood, E. J. & Dunstone, N. J. The influence of anthropogenic aerosol on multi-decadal variations of historical global climate. Environ. Res. Lett. 8, 024033 (2013).

    Article  Google Scholar 

  21. Shindell, D. T., Faluvegi, G., Rotstayn, L. & Milly, G. Spatial patterns of radiative forcing and surface temperature response. J. Geophys. Res. 120, 5385–5403 (2015).

    Google Scholar 

  22. Rotstayn, L. D., Collier, M. A., Shindell, D. T. & Boucher, O. Why does aerosol forcing control historical global-mean surface temperature change in CMIP5 models? J. Clim. 28, 6608–6625 (2015).

    Article  Google Scholar 

  23. Ming, Y. & Ramaswamy, V. A model investigation of aerosol-induced changes in tropical circulation. J. Clim. 24, 5125–5133 (2011).

    Article  Google Scholar 

  24. Bollasina, M. A., Ming, Y. & Ramaswamy, V. Anthropogenic aerosols and the weakening of the South Asian summer monsoon. Science 334, 502–505 (2011).

    Article  Google Scholar 

  25. Ocko, I. B., Ramaswamy, V. & Ming, Y. Contrasting climate responses to the scattering and absorbing features of anthropogenic aerosol forcings. J. Clim. 27, 5329–5345 (2014).

    Article  Google Scholar 

  26. Rotstayn, L. D., Collier, M. A. & Luo, J.-J. Effects of declining aerosols on projections of zonally averaged tropical precipitation. Environ. Res. Lett. 10, 044018 (2015).

    Article  Google Scholar 

  27. Soden, B. J. et al. Quantifying climate feedbacks using radiative kernels. J. Clim. 21, 3504–3520 (2008).

    Article  Google Scholar 

  28. Taylor, K. E., Stouffer, R. J. & Meehl, G. A. An overview of CMIP5 and the experiment design. Bull. Am. Meteorol. Soc. 93, 485–498 (2012).

    Article  Google Scholar 

  29. Xie, S.-P. et al. Global warming pattern formation: sea surface temperature and rainfall. J. Clim. 23, 966–986 (2010).

    Article  Google Scholar 

  30. Rotstayn, L. D., Collier, M. A., Chrastansky, A., Jeffrey, S. J. & Luo, J.-J. Projected effects of declining aerosols in RCP4.5: unmasking global warming? Atmos. Chem. Phys. 13, 10883–10905 (2013).

    Article  Google Scholar 

  31. Allen, R. J. A 21st century northward tropical precipitation shift caused by future anthropogenic aerosol reductions. J. Geophys. Res. 120, 9087–9102 (2015).

    Article  Google Scholar 

  32. Held, I. & Soden, B. J. Robust responses of the hydrological cycle to global warming. J. Clim. 19, 5686–5699 (2006).

    Article  Google Scholar 

  33. Dong, B. & Sutton, R. Dominant role of greenhouse-gas forcing in the recovery of Sahel rainfall. Nat. Clim. Change 5, 757–760 (2015).

    Article  Google Scholar 

  34. Morice, C. P., Kennedy, J. J., Rayner, N. A. & Jones, P. D. Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: the HadCRUT4 data set. J. Geophys. Res. 117, D08101 (2012).

    Article  Google Scholar 

  35. Chadwick, R., Boutle, I. & Martin, G. Spatial patterns of precipitation change in CMIP5: why the rich do not get richer in the tropics. J. Clim. 26, 3803–3822 (2013).

    Article  Google Scholar 

  36. He, J. & Soden, B. J. The impact of SST biases on projections of anthropogenic climate change: a greater role for atmosphere-only models? Geophys. Res. Lett. 43, 7745–7750 (2016).

    Article  Google Scholar 

  37. Peterson, T. C. & Vose, R. S. An overview of the global historical climatology network temperature database. Bull. Am. Meteorol. Soc. 78, 2837–2849 (1997).

    Article  Google Scholar 

  38. Liu, C. & Allan, R. P. Observed and simulated precipitation responses in wet and dry regions 1850–2100. Environ. Res. Lett. 8, 034002 (2013).

    Article  Google Scholar 

  39. Allan, R. P. Dichotomy of drought and deluge. Nat. Geosci. 7, 700–701 (2014).

    Article  Google Scholar 

  40. Norris, J. R. et al. Evidence for climate change in the satellite cloud record. Nature 536, 72–75 (2016).

    Article  Google Scholar 

  41. Zelinka, M. D., Andrews, T., Forster, P. M. & Taylor, K. E. Quantifying components of aerosol–cloud-radiation interactions in climate models. J. Geophys. Res. 119, 7599–7615 (2014).

    Google Scholar 

  42. Hansen, J., Ruedy, R., Sato, M. & Lo, K. Global surface temperature change. Rev. Geophys. 48, RG4004 (2010).

    Article  Google Scholar 

  43. Chung, E.-S. & Soden, B. J. An assessment of direct radiative forcing, radiative adjustments, and radiative feedbacks in coupled ocean–atmosphere models. J. Clim. 28, 4152–4170 (2015).

    Article  Google Scholar 

  44. Collins, W. D. et al. Radiative forcing by well-mixed greenhouse gases: estimates from climate models in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). J. Geophys. Res. 111, D14317 (2006).

    Article  Google Scholar 

  45. Soden, B. J., Broccoli, A. J. & Hemler, R. S. On the use of cloud forcing to estimate cloud feedback. J. Clim. 17, 3661–3665 (2004).

    Article  Google Scholar 

  46. Taylor, K. E. et al. Estimating shortwave radiative forcing and response in climate models. J. Clim. 20, 2530–2543 (2007).

    Article  Google Scholar 

Download references

Acknowledgements

We acknowledge the World Climate Research Programme’s Working Group on Coupled Modeling, which is responsible for CMIP, and we thank the climate modelling groups (listed in Supplementary Table 1 of this study) for producing and making available their model output. For CMIP the US Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. This study was supported by grants from the NASA ROSES Program.

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E.-S.C. and B.J.S. designed the study, performed the analysis, and wrote the paper.

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Correspondence to Brian J. Soden.

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Chung, ES., Soden, B. Hemispheric climate shifts driven by anthropogenic aerosol–cloud interactions. Nature Geosci 10, 566–571 (2017). https://doi.org/10.1038/ngeo2988

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