Cited by 99Climate variability and modelsHydrology and Drought AnalysisGeology and Paleoclimatology Research

Assessing recovery and change in West Africa's rainfall regime from a 161‐year record

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Nicholson, Sharon E., Fink, Andreas H., Funk, Chris·2018·International Journal of Climatology

Abstract

The Sahel region is known for the multi‐decadal occurrence of severe drought that commenced in the late 1960s. A still open question is whether or not the region's rainfall has returned to “normal.” This paper provides a compelling answer to that question by examining the longest and most comprehensive gauge series for the region ever published. It extends from 1854 to 2014 and is based on 602 gauge records. A comparative series for the Guinea Coast region to the south is also presented, as the two regions collectively provide insight into the long‐term variability of the West African monsoon. In contrast to many previous studies, here the question of recovery and regime change is not restricted to the core of the Sahelian rainy season (July–September), but is separately discussed also for the coastal phase (April–May), transition phase (June), Sahelian phase (July–September) and the second transition phase (October–November) of the West African monsoon. These analyses suggest that full recovery from the droughts of the 1970s and 1980s has not occurred that a major change in the rainfall regime occurred around 1968 and that since that time large‐scale teleconnections have also changed markedly. The shift post‐1968 is evident in all phases of the monsoon except the coastal phase, in which a change to drier conditions occurred a decade later. Overall, recovery has been greater in the east than in the west, creating a change in the climatological east–west rainfall gradient. The drier post‐1968 conditions appear to be associated with a general weakening of the intensity of the West African monsoon and only a small southwards displacement of the rainfall maximum. These changes have strong implications for the future of this region and for seasonal prediction.

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  • For much of the African continent, particularly the Sahel, the most salient consequence of climate change has been rainfall persistently below the long-run average.

    “For much of the African continent, particularly the Sahel region, the most salient consequence of climate change has been rainfall that is persistently below the long-run average.”

    From Transhumant Pastoralism, Climate Change, and Conflict in Africa (2025) · cites this paper as Nicholson, Fink and Funk, 2018

    The Summary and Conclusions (page not supplied) report that Sahel rainfall since the 1990s remained predominantly below average despite some recovery and occasional very wet years. The paper studies the Sahel and Guinea Coast, not much of Africa, and does not establish below-average rainfall as the most salient consequence of climate change. (LLM, conf=0.88)

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Cites

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Research works printed but not linked: 7

  1. Gershunov, A., Schneider, N. and Barnett, T. (2001) Low frequency modulation of the ENSO-Indian monsoon rainfall relationship: signal or noise? Journal of Climate, 14, 2482-2492.
  2. Janicot, S. (1992) Spatiotemporal variability of West African rainfall. Part II: associated surface and airmass characteristics. Journal of Climate, 5(5), 499-511.
  3. Lamb, P.J. (1978a) Case studies of tropical Atlantic surface circulation patterns during recent sub-Saharan weather anomalies: 1967 and 1968. Monthly Weather Review, 106(4), 482-491.
  4. Nicholson, S.E. (1980) The nature of rainfall fluctuations in subtropical West Africa. Monthly Weather Review, 108(4), 473-487.
  5. Nicholson, S.E. (1986) The spatial coherence of African rainfall anomalies: interhemispheric teleconnections. Journal of Climate and Applied Meteorol- ogy, 25(10), 1355-1381.
  6. Nicholson, S.E. (1993) An overview of African rainfall fluctuations of the last decade. Journal of Climate, 6, 1463-1466.
  7. Nicholson, S.E., Some, B. and Kone, B. (2000) An analysis of recent rainfall conditions in West Africa, including the rainy seasons of the 1997 El Niño and the 1998 La Niña years. Journal of Climate, 13(14), 2628-2640.

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Authors
Nicholson, S. E., Fink, A. H., & Funk, C.
Affiliations
  • Florida State University (US)
  • Karlsruhe Institute of Technology (DE)
  • United States Geological Survey (US)
Corresponding author
Nicholson, Sharon E.
Venue
International Journal of Climatology
Publisher
Wiley
Published
2018-04-06
Volume
38
Issue
10
Pages
3770-3786
ISSN
  • 0899-8418 (ISSN-L)
  • 1097-0088
OpenAlex
W2797858754
Cited by
99
References
52
Citations by year
2026: 10 · 2025: 17 · 2024: 11 · 2023: 12 · 2022: 13 · 2021: 9 · 2020: 17 · 2019: 6 · 2018: 3 · 2017: 1
FWCI
5.12
Type
journal article
Language
en
Open access
Locations
International Journal of Climatology (publishedVersion)
Funders
  • Division of Atmospheric and Geospace Sciences (AGS1445605)
  • U.S. Geological Survey (G009AC000001)
  • Bundesministerium für Bildung und Forschung (01LP1520D)
Topics
  • Physical Sciences › Environmental Science › Global and Planetary Change › Climate variability and models
  • Physical Sciences › Environmental Science › Global and Planetary Change › Hydrology and Drought Analysis
  • Physical Sciences › Earth and Planetary Sciences › Atmospheric Science › Geology and Paleoclimatology Research
Keywords
tipping points, West African monsoon, long-term rainfall variability, teleconnections, monsoon weakening, Guinea coast, seasonal forecasting

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