Changes in intense rainfall events and dry periods across Africa in the twenty-first century

  • Fan Han
  • Kerry H. CookEmail author
  • Edward K. Vizy


A statistical framework for evaluating changes in extreme events is proposed and applied to evaluate a 20-member, regional climate model ensemble simulation with 30-km resolution. The model is found to represent the statistics and distributions of extreme events, including observed wet day characteristics, wet/dry days, and wet/dry spell characteristics, reasonably across Africa. Simulations of the mid-twenty-first and late-twenty-first century project statistically-significant changes in these societally-relevant climate characteristics in three regions. Intensification of rainfall is projected for the Sahel rainy season, including large increases in wet spell frequency, wet spell duration, and wet spell intensity. These changes are statistically significant at mid-twenty-first century and become more spatially robust by the end of the century. A weaker intensified rainfall trend is also projected over East Africa, for northern Ethiopia in boreal summer, Tanzania in boreal winter, and southern Ethiopia, Somalia, and the Lake Victoria region in boreal fall. The changes are significant in scattered regions at mid-twenty-first century, but widespread and highly significant by the end of the century. In contrast, increased dry periods is projected for parts of southern Africa (Angola, Zambia, Malawi), including 50–100% reductions in wet spell frequency annually and increases in dry spell duration in austral spring. The spatial coherence and rigorous statistical analysis of the projected changes combined with their physical consistency with the findings of previous studies support confidence in these results.


Extreme events Drought African climate projection Sahel rainfall Southern Africa climate change East Africa climate change Sahel climate change 



Support from NSF Award #1356386 is gratefully acknowledged. The Texas Advanced Computing Center at the University of Texas at Austin provided the high-performance computing and database resources.


  1. Abiodun BJ, Omar SA, Lennard C, Jack C (2016) Using regional climate models to simulate extreme rainfall events in the Western Cape, South Africa. Int J Climatol 36:689–705CrossRefGoogle Scholar
  2. Alexander LV, Uotila P, Nicholls N (2009) Influence of sea surface temperature variability on global temperature and precipitation extremes. J Geophys Res. Google Scholar
  3. Almazroui M, Islam MN, Dambul R, Jones PD (2014) Trends of temperature extremes in Saudi Arabia. Int J Climatol 34:808–826. CrossRefGoogle Scholar
  4. Boyle J, Klein SA (2010) Impact of horizontal resolution on climate model forecasts of tropical precipitation and diabatic heating for the TWP-ICE period. J Geophys Res. Google Scholar
  5. Changyong FE, Hongyue WA, Naiji LU, Tian CH, Hua HE, Ying LU (2014) Log-transformation and its implications for data analysis. Shanghai Arch Psychiatry 26:105Google Scholar
  6. Chen F, Dudhia J (2001) Coupling an advanced land surface–hydrology model with the Penn State–NCAR MM5 modeling system. Part I: Model implementation and sensitivity. Mon Weather Rev 129:569–585CrossRefGoogle Scholar
  7. Chen SH, Sun WY (2002) A one-dimensional time dependent cloud model. J Meteorol Soc Jpn Ser II 80:99–118CrossRefGoogle Scholar
  8. Cook KH (2000) The South Indian convergence zone and interannual rainfall variability over southern Africa. J Clim 13:3789–3804CrossRefGoogle Scholar
  9. Cook KH (2001) A Southern Hemisphere wave response to ENSO with implications for southern Africa precipitation. J Atmos Sci 58:2146–2162CrossRefGoogle Scholar
  10. Cook KH, Vizy EK (2012) Impact of climate change on mid-twenty-first century growing seasons in Africa. Clim Dyn 39:2937–2955. CrossRefGoogle Scholar
  11. Cook KH, Vizy EK (2013) Projected changes in East African rainy seasons. J Clim 26:5931–5948. CrossRefGoogle Scholar
  12. Cook KH, Vizy EK (2015) Detection and analysis of an amplified warming of the Sahara Desert. J Clim 28:6560–6580. CrossRefGoogle Scholar
  13. Crétat J, Vizy EK, Cook KH (2014) How well are daily intense rainfall events captured by current climate models over Africa? Clim Dyn 42:2691–2711. CrossRefGoogle Scholar
  14. Dee DP, Uppala SM, Simmons AJ, Berrisford P, Poli P, Kobayashi S, Andrae U, Balmaseda MA, Balsamo G, Bauer DP, Bechtold P (2011) The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Q J R Meteorol Soc 137:553–597CrossRefGoogle Scholar
  15. Diallo I, Giorgi F, Deme A, Tall M, Mariotti L, Gaye AT (2016) Projected changes of summer monsoon extremes and hydroclimatic regimes over West Africa for the twenty-first century. Clim Dyn 47:3931–3954CrossRefGoogle Scholar
  16. Dong B, Sutton R (2015) Dominant role of greenhouse-gas forcing in the recovery of Sahel rainfall. Nat Clim Change 5:757. CrossRefGoogle Scholar
  17. Dosio A, Panit HJ (2016) Climate change projections for CORDEX-Africa with COSMO-CLM regional climate model and differences with the driving global climate models. Clim Dyn 46:1599–1625CrossRefGoogle Scholar
  18. Frehlich R, Sharman R (2008) The use of structure functions and spectra from numerical model output to determine effective model resolution. Mon Weather Rev 136:1537–1553CrossRefGoogle Scholar
  19. Frei C, Schöll R, Fukutome S, Schmidli J, Vidale PL (2006) Future change of precipitation extremes in Europe: intercomparison of scenarios from regional climate models. J Geophys Res. Google Scholar
  20. Frich P, Alexander LV, Della-Marta PM, Gleason B, Haylock M, Tank AK, Peterson T (2002) Observed coherent changes in climatic extremes during the second half of the twentieth century. Clim Res 19:193–212CrossRefGoogle Scholar
  21. Gelaro R, McCarty W, Suárez MJ, Todling R, Molod A, Takacs L, Randles CA, Darmenov A, Bosilovich MG, Reichle R, Wargan K (2017) The modern-era retrospective analysis for research and applications, version 2 (MERRA-2). J Clim 30:5419–5454CrossRefGoogle Scholar
  22. Giorgi F, Jones C, Asrar GR (2009) Addressing climate information needs at the regional level: the CORDEX framework. World Meteorol Org (WMO) Bull 58:175Google Scholar
  23. Guilloteau C, Foufoula-Georgiou E, Kummerow CD (2017) Global multiscale evaluation of satellite passive microwave retrieval of precipitation during the TRMM and GPM eras: effective resolution and regional diagnostics for future algorithm development. J Hydrometeorol 18:3051–3070. CrossRefGoogle Scholar
  24. Hagos SM, Cook KH (2008) Ocean warming and late-twentieth-century Sahel drought and recovery. J Clim 21:3797–3814CrossRefGoogle Scholar
  25. Hernández-Díaz L, Laprise R, Sushama L, Martynov A, Winger K, Dugas B (2013) Climate simulation over CORDEX Africa domain using the fifth-generation Canadian Regional Climate Model (CRCM5). Clim Dyn 40:1415–1433. CrossRefGoogle Scholar
  26. Hong SY, Noh Y, Dudhia J (2006) A new vertical diffusion package with an explicit treatment of entrainment processes. Mon Weather Rev 134:2318–2341CrossRefGoogle Scholar
  27. Huffman GJ, Bolvin DT, Nelkin EJ, Wolff DB, Adler RF, Gu G, Hong Y, Bowman KP, Stocker EF (2007) The TRMM multisatellite precipitation analysis (TMPA): Quasi-global, multiyear, combined-sensor precipitation estimates at fine scales. J Hydrometeorol 8:38–55. CrossRefGoogle Scholar
  28. IPCC (2014) Climate change 2014: synthesis report. In: Core Writing Team, Pachauri RK, Meyer LA (eds) Contribution of working groups I, II and III to the fifth assessment report of the intergovernmental panel on climate change. IPCC, Geneva, p 151Google Scholar
  29. Janowiak JE (1988) An investigation of interannual rainfall variability in Africa. J Clim 1:240–255CrossRefGoogle Scholar
  30. Kain JS (2004) The Kain–Fritsch convective parameterization: an update. J Appl Meteorol 43:170–181CrossRefGoogle Scholar
  31. Kanamitsu M, Ebisuzaki W, Woollen J, Yang SK, Hnilo JJ, Fiorino M, Potter GL (2002) NCEP-DOE AMIP-II reanalysis (R-2). Bull Am Meteor Soc 83:1631–1643. CrossRefGoogle Scholar
  32. Katz RW, Acero JG (1994) Sensitivity analysis of extreme precipitation events. Int J Climatol 14:985–999CrossRefGoogle Scholar
  33. Katz RW, Brown BG (1992) Extreme events in a changing climate: variability is more important than averages. Clim Change 21:289–302CrossRefGoogle Scholar
  34. Katz RW, Parlange MB, Naveau P (2002) Statistics of extremes in hydrology. Adv Water Resour 25:1287–1304CrossRefGoogle Scholar
  35. Kobayashi S, Ota Y, Harada Y, Ebita A, Moriya M, Onoda H, Onogi K, Kamahori H, Kobayashi C, Endo H, Miyaoka K (2015) The JRA-55 reanalysis: general specifications and basic characteristics. J Meteorol Soc Jpn Ser II 93:5–48. CrossRefGoogle Scholar
  36. Lebel T, Ali A (2009) Recent trends in the Central and Western Sahel rainfall regime (1990–2007). J Hydrol 375:52–64. CrossRefGoogle Scholar
  37. Li F, Collins WD, Wehner MF, Williamson DL, Olson JG (2011) Response of precipitation extremes to idealized global warming in an aqua-planet climate model: towards a robust projection across different horizontal resolutions. Tellus A 63:876–883. CrossRefGoogle Scholar
  38. Liebmann B, Hoerling MP, Funk C, Bladé I, Dole RM, Allured D, Quan X, Pegion P, Eischeid JK (2014) Understanding recent Eastern Horn of Africa rainfall variability and change. J Clim 27:8630–8645. CrossRefGoogle Scholar
  39. Lyon B, DeWitt DG (2012) A recent and abrupt decline in the East African long rains. Geophys Res Lett 39:2. CrossRefGoogle Scholar
  40. Mlawer EJ, Taubman SJ, Brown PD, Iacono MJ, Clough SA (1997) Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave. J Geophys Res 102:16663–16682CrossRefGoogle Scholar
  41. Neupane N, Cook KH (2013) A nonlinear response of Sahel rainfall to Atlantic warming. J Climate 26:7080–7096CrossRefGoogle Scholar
  42. Nicholson SE (2001) Climatic and environmental change in Africa during the last two centuries. Clim Res 17:123–144CrossRefGoogle Scholar
  43. Nicholson S (2005) On the question of the “recovery” of the rains in the West African Sahel. J Arid Environ 63:615–641. CrossRefGoogle Scholar
  44. Nikulin G, Jones C, Giorgi F, Asrar G, Büchner M, Cerezo-Mota R, Christensen OB, Déqué M, Fernandez J, Hänsler A, van Meijgaard E (2012) Precipitation climatology in an ensemble of CORDEX-Africa regional climate simulations. J Clim 25:6057–6078. CrossRefGoogle Scholar
  45. Omondi PAO, Awange JL, Forootan E, Ogallo LA, Barakiza R, Girmaw GB, Fesseha I, Kululetera V, Kilembe C, Mbati MM, Kilavi M (2014) Changes in temperature and precipitation extremes over the Greater Horn of Africa region from 1961 to 2010. Int J Climatol 34:1262–1277. CrossRefGoogle Scholar
  46. Panthou G, Vischel T, Lebel T (2014) Recent trends in the regime of extreme rainfall in the Central Sahel. Int J Climatol 34:3998–4006. CrossRefGoogle Scholar
  47. Parry ML, Carter TR (1985) The effect of climatic variations on agricultural risk. Clim Change 7:95–110. CrossRefGoogle Scholar
  48. Pinto I, Lennard C, Tadross M, Hewitson B, Dosio A, Nikulin G, Panitz HJ, Shongwe ME (2016) Evaluation and projections of extreme precipitation over southern Africa from two CORDEX models. Clim Change 135:655–668CrossRefGoogle Scholar
  49. Pohl B, Macron C, Monerie PA (2017) Fewer rainy days and more extreme rainfall by the end of the century in Southern Africa. Sci Rep 7:46466. CrossRefGoogle Scholar
  50. Sanogo S, Fink AH, Omotosho JA, Ba A, Redl R, Ermert V (2015) Spatio-temporal characteristics of the recent rainfall recovery in West Africa. Int J Climatol 35:4589–4605. CrossRefGoogle Scholar
  51. Sapiano MRP, Arkin PA (2009) An intercomparison and validation of high-resolution satellite precipitation estimates with 3-hourly gauge data. J Hydrometeorol 10:149–166. CrossRefGoogle Scholar
  52. Serrano SM, Beguería S, López-Moreno JI (2010) A multiscalar drought index sensitive to global warming: the standardized precipitation evapotranspiration index. J Clim 23:1696–1718. CrossRefGoogle Scholar
  53. Sheikh MM, Manzoor N, Ashraf J, Adnan M, Collins D, Hameed S, Manton MJ, Ahmed AU, Baidya SK, Borgaonkar HP, Islam N (2015) Trends in extreme daily rainfall and temperature indices over South Asia. Int J Climatol 35:1625–1637. CrossRefGoogle Scholar
  54. Shiferaw A, Tadesse T, Rowe C, Oglesby R (2018) Precipitation extremes in dynamically downscaled climate scenarios over the greater horn of Africa. Atmosphere 9:112CrossRefGoogle Scholar
  55. Sillmann J, Kharin VV, Zhang X, Zwiers FW, Bronaugh D (2013a) Climate extremes indices in the CMIP5 multimodel ensemble: Part 1. Model evaluation in the present climate. J Geophys Res 118:1716–1733. Google Scholar
  56. Sillmann J, Kharin VV, Zwiers FW, Zhang X, Bronaugh D (2013b) Climate extremes indices in the CMIP5 multimodel ensemble: Part 2. Future climate projections. J Geophys Res 118:2473–2493. Google Scholar
  57. Singh D, Tsiang M, Rajaratnam B, Diffenbaugh NS (2014) Observed changes in extreme wet and dry spells during the South Asian summer monsoon season. Nature Climate Change 4:456. CrossRefGoogle Scholar
  58. Skamarock WC (2004) Evaluating mesoscale NWP models using kinetic energy spectra. Mon Weather Rev 132:3019–3032CrossRefGoogle Scholar
  59. Skamarock WC, Klemp JB, Dudhia J, Gill DO, Barker DM, Wang W, Powers JG (2005) A description of the advanced research WRF version 2 (No. NCAR/TN-468 + STR). Mesoscale and Microscale Meteorology Division, National Center for Atmospheric Research Boulder, CO, USA.
  60. Sun Y, Solomon S, Dai A, Portmann RW (2006) How often does it rain? J Clim 19:916–934CrossRefGoogle Scholar
  61. Taylor CM, Belušić D, Guichard F, Parker DJ, Vischel T, Bock O, Harris PP, Janicot S, Klein C, Panthou G (2017) Frequency of extreme Sahelian storms tripled since 1982 in satellite observations. Nature 544:475. CrossRefGoogle Scholar
  62. Tian Y, Peters-Lidard CD (2010) A global map of uncertainties in satellite-based precipitation measurements. Geophys Res Lett 37:24. CrossRefGoogle Scholar
  63. Tian Y, Peters-Lidard CD, Eylander JB, Joyce RJ, Huffman GJ, Adler RF, Hsu KL, Turk FJ, Garcia M, Zeng J (2009) Component analysis of errors in satellite-based precipitation estimates. J Geophys Res. Google Scholar
  64. Viste E, Korecha D, Sorteberg A (2013) Recent drought and precipitation tendencies in Ethiopia. Theoret Appl Climatol 112:535–551. CrossRefGoogle Scholar
  65. Vizy EK, Cook KH (2012) Mid-twenty-first-century changes in extreme events over northern and tropical Africa. J Clim 25:5748–5767. CrossRefGoogle Scholar
  66. Vizy EK, Cook KH (2017) Seasonality of the observed amplified Sahara warming trend and implications for Sahel rainfall. J Clim 30:3073–3094CrossRefGoogle Scholar
  67. Vizy EK, Cook KH, Crétat J, Neupane N (2013) Projections of a wetter Sahel in the twenty-first century from global and regional models. J Clim 26:4664–4687. CrossRefGoogle Scholar
  68. Vizy EK, Cook KH, Chimphamba J, McCusker B (2015) Projected changes in Malawi’s growing season. Clim Dyn 45:1673–1698. CrossRefGoogle Scholar
  69. Washington R, Harrison M, Conway D, Black E, Challinor A, Grimes D, Jones R, Morse A, Kay G, Todd M (2006) African climate change: taking the shorter route. Bull Am Meteor Soc 87:1355–1366. CrossRefGoogle Scholar
  70. Wigley TM (1985) Climatology: impact of extreme events. Nature 316:106–107CrossRefGoogle Scholar
  71. Xu Z, Chang P, Richter I, Tang G (2014) Diagnosing southeast tropical Atlantic SST and ocean circulation biases in the CMIP5 ensemble. Clim Dyn 43:3123–3145. CrossRefGoogle Scholar
  72. Zhang X, Alexander L, Hegerl GC, Jones P, Tank AK, Peterson TC, Trewin B, Zwiers FW (2011) Indices for monitoring changes in extremes based on daily temperature and precipitation data. Wiley Interdiscip Rev 2:851–870. Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Geological Sciences, Jackson School of GeosciencesThe University of Texas at AustinAustinUSA

Personalised recommendations