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Anthropogenic aerosol forcing of Atlantic tropical storms


The frequency of tropical storms in the North Atlantic region varies markedly on decadal timescales1,2,3,4, with profound socio-economic impacts5,6. Climate models largely reproduce the observed variability when forced by observed sea surface temperatures1,8,10. However, the relative importance of natural variability and external influences such as greenhouse gases, dust, sulphate and volcanic aerosols on sea surface temperatures, and hence tropical storms, is highly uncertain11,12,13,14,15,16. Here, we assess the effect of individual climate drivers on the frequency of North Atlantic tropical storms between 1860 and 2050, using simulations from a collection of climate models17. We show that anthropogenic aerosols lowered the frequency of tropical storms over the twentieth century. However, sharp declines in anthropogenic aerosol levels over the North Atlantic at the end of the twentieth century allowed the frequency of tropical storms to increase. In simulations with a model that comprehensively incorporates aerosol effects (HadGEM2-ES; ref. 18), decadal variability in tropical storm frequency is well reproduced through aerosol-induced north–south shifts in the Hadley circulation. However, this mechanism changes in future projections. Our results raise the possibility that external factors, particularly anthropogenic aerosols, could be the dominant cause of historical tropical storm variability, and highlight the potential importance of future changes in aerosol emissions.

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Figure 1: Comparing observed and modelled TS-related indices.
Figure 2: Impact of external forcing on historical TSs.
Figure 3: The impact of anthropogenic aerosols (ALL–AERO1860) in HadGEM2-ES over the historical period.
Figure 4: Maps and cross-sections for near-term future (2010–2040).


  1. 1

    Knutson, T. R. et al. Tropical cyclones and climate change. Nature Geosci. 3, 157–163 (2010).

    Article  Google Scholar 

  2. 2

    Goldenberg, S. I., Landsea, C. W., Mestas-Nuñez, A. M. & Gray, W. M. The recent increase in Atlantic hurricane activity: Causes and implications. Science 293, 474–479 (2001).

    Article  Google Scholar 

  3. 3

    Klotzbach, P. J. & Gray, W. M. Multidecadal variability in North Atlantic tropical cyclone activity. J. Clim. 21, 3929–3935 (2008).

    Article  Google Scholar 

  4. 4

    Nigam, S. & Guan, B. Atlantic tropical cyclones in the twentieth century: Natural variability and secular change in cyclone count. Clim. Dynam. 36, 2279–2293 (2011).

    Article  Google Scholar 

  5. 5

    Rappaport, E. N. Loss of life in the United States associated with recent Atlantic tropical cyclones. Bull. Am. Meteorol. Soc. 81, 2065–2073 (2000).

    Article  Google Scholar 

  6. 6

    Pielke, R. A. et al. Normalized hurricane damage in the United States: 1900–2005. Nat. Hazards Rev. 9, 29–42 (2008).

    Article  Google Scholar 

  7. 7

    Smith, D. M. et al. Skilful multi-year predictions of Atlantic hurricane frequency. Nature Geosci. 3, 846–849 (2010).

    Article  Google Scholar 

  8. 8

    Zhao, M. & Held, I. M. TC-permitting GCM simulations of hurricane frequency response to sea surface temperature anomalies projected for the late-twenty-first century. J. Clim. 25, 2995–3009 (2012).

    Article  Google Scholar 

  9. 9

    Villarini, G. & Vecchi, G. A. Twenty-first-century projections of North Atlantic tropical storms from CMIP5 models. Nature Clim. 2, 604–607 (2012).

    Article  Google Scholar 

  10. 10

    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 

  11. 11

    Ting, M., Kushnir, Y., Seager, R. & Li, C. Forced and internal twentieth-century SST trends in the North Atlantic. J. Clim. 22, 1469–1481 (2009).

    Article  Google Scholar 

  12. 12

    Otterå, O. H., Bentsen, M., Drange, H. & Suo, L. External forcing as a metronome for Atlantic multidecadal variability. Nature Geosci. 3, 688–694 (2010).

    Article  Google Scholar 

  13. 13

    Booth, B. B. B., Dunstone, N. J., Halloran, P. R., Andrews, T. & Bellouin, N. Aerosols implicated as a prime driver of twentieth-century North Atlantic climate variability. Nature 484, 228–232 (2012).

    Article  Google Scholar 

  14. 14

    Mann, M. E. & Emanuel, K. A. Atlantic hurricane trends linked to climate change. Eos, Trans. Am. Geophys. Union 87, 233–244 (2006).

    Article  Google Scholar 

  15. 15

    Wang, C, Dong, S, Evan, A. T., Foltz, G. R. & Lee, S-K. Multidecadal covariability of North Atlantic sea surface temperature, African dust, Sahel rainfall, and Atlantic hurricanes. J. Clim. 25, 5404–5415 (2012).

    Article  Google Scholar 

  16. 16

    Evan, A. T. Atlantic hurricane activity following two major volcanic eruptions. J. Geophys. Res. 117, D06101 (2012).

    Google Scholar 

  17. 17

    Taylor, K. E., Stouffer, R. J. & Meehl, G. A. An Overview of CMIP5 and the experiment design. BAMS 93, 485–498 (2012).

    Article  Google Scholar 

  18. 18

    Collins, W. J. et al. Development and evaluation of an Earth-System model-HadGEM2. Geosci. Model Dev. 4, 1051–1075 (2011).

    Article  Google Scholar 

  19. 19

    Latif, M. N., Keenlyside, N. & Bader, J. Tropical sea surface temperature, vertical wind shear, and hurricane development. Geophys. Rev. Lett. 34, L01710 (2007).

    Article  Google Scholar 

  20. 20

    Bellouin, N. et al. Aerosol forcing in the Climate Model Intercomparison Project (CMIP5) simulations by HadGEM2-ES and the role of ammonium nitrate. J. Geophys. Res. 116, D20206 (2011).

    Article  Google Scholar 

  21. 21

    Clement, A. C., Burgman, R. & Norris, J. R. Observational and model evidence for positive low-level cloud feedback. Science 325, 460–464 (2009).

    Article  Google Scholar 

  22. 22

    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 

  23. 23

    Dunstone, N. J., Smith, D. M. & Eade, R. Multi-year predictability of the tropical Atlantic atmosphere driven by the high latitude North Atlantic Ocean. Geophys. Res. Lett. 38, L14701 (2011).

    Article  Google Scholar 

  24. 24

    Chang, C. Y., Chiang, J. C. H., Wehner, M. F., Friedman, A. & Ruedy, R. Sulfate aerosol control of tropical Atlantic climate over the 20th century. J. Clim. 24, 2540–2555 (2011).

    Article  Google Scholar 

  25. 25

    Vimont, D. J. & Kossin, J. P. The Atlantic Meridional Mode and hurricane activity. Geophys. Res. Lett. 34, L07709 (2007).

    Article  Google Scholar 

  26. 26

    Allen, R. J., Sherwood, S. C., Norris, J. R. & Zender, C. S. Recent North Hemisphere tropical expansion primarily driven by black carbon and tropospheric ozone. Nature 485, 350–354 (2012).

    Article  Google Scholar 

  27. 27

  28. 28

    Landsea, C. W., Vecchi, G. A., Bengtsson, L. & Knutson, T. R. Impact of duration threshold on Atlantic tropical cyclone counts. J. Clim. 23, 2508–2519 (2010).

    Article  Google Scholar 

  29. 29

    Rayner, N. A. et al. Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J. Geophys. Res. 108, 4407 (2003).

    Article  Google Scholar 

  30. 30

    Compo, G. L. et al. The twentieth century reanalysis project. Quart. J. R. Meteorol. Soc. 137, 1–28 (2011).

    Article  Google Scholar 

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We are very grateful for discussion and input from N. Bellouin. We also thank G. Jones, P. Halloran and J. Hughes for setting up and running the CMIP5 integrations of HadGEM2-ES. We acknowledge the modelling groups, the Program for Climate Model Diagnosis and Intercomparison (PCMDI) and the World Climate Research Programme’s Working Group on Coupled Modelling (WGCM), which is responsible for CMIP, and we thank the climate modelling groups (listed in Supplementary Fig. S5 of this paper) 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. The authors were supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101) and the EU FP7 THOR project.

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N.J.D. and D.M.S. led the analysis. N.J.D., D.M.S., B.B.B.B. and L.H. wrote the paper. R.E. performed the storm tracking and commented on the manuscript.

Corresponding author

Correspondence to N. J. Dunstone.

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The authors declare no competing financial interests.

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Dunstone, N., Smith, D., Booth, B. et al. Anthropogenic aerosol forcing of Atlantic tropical storms. Nature Geosci 6, 534–539 (2013).

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