@article{fdi:010087000,
  title = {{C}apturing and attributing the rainfall regime intensification in the {W}est {A}frican {S}ahel with {CMIP}6 models},
  author = {{C}hagnaud, {G}. and {P}anthot, {G}. and {V}ischel, {T}. and {L}ebel, {T}hierry},
  editor = {},
  language = {{ENG}},
  abstract = {{R}ainfall in the {S}ahel is extremely variable on daily to multidecadal time scales, challenging climate models to realistically simulate its past and future evolution and questioning their relevance for defining suitable climate change adaptation strategies. {I}mproving confidence in climate models may be achieved by (i) evaluating their capacity for repro-ducing observed climatic evolution and (ii) attributing these evolutions. {M}oreover, there is a need to consider relevant cli-matic indicators, from an end-user point of view. {F}ully coupled ({CMIP}6-{AOGCM}) models with idealized detection and attribution forcings ({DAMIP}) as well as atmosphere-only simulations ({AMIP}) are used to investigate the respective roles of external forcing factors and internal climate variability in the observed intensification of the {S}ahelian rainfall regime. {W}e show that {CMIP}6 models contain signs of the intensification of the rainfall regime as detected over the past 35 years from a regional daily observations network. {B}oth the increase in intensity and occurrence of wet days, as well as that of ex-treme daily rainfall, are remarkably well reproduced by historical simulations incorporating anthropogenic forcing factors, with anthropogenic aerosols contributing the largest share of this trend. {T}hough more strongly affected by model structure uncertainty, the greenhouse gas forcing also displays noticeably robust features. {M}odels are shown to fail at simulating the observed dry extreme evolution. {T}hese findings give incentive for further investigating the underlying physical mechanisms that drive the {S}ahelian rainfall regime evolution at regional to subregional scales. {F}urthermore, future hydroclimatic trajec-tories in the {S}ahel should be explored, though particular caution is required as to which rainfall indicator to consider. {SIGNIFICANCE} {STATEMENT}: {T}he rainfall regime at a particular location is crucial to human and ecosystem liveli-hoods. {C}hanges in rainfall regime characteristics on multidecadal time scales result from both the effects of external forcing factors on the climate and of its internal variability, with this latter aspect becoming more prominent on small spatial scales. {I}n this study, several state-of-the-art climate simulations are used to document the rainfall regime evolu-tion of the past 65 years in the {S}ahel, in terms of amplitude, timing, and causes. {I}t is shown that large-scale anthropo-genic factors have a substantial imprint, modulated to some extent by internal variability. {T}hese findings demonstrate that coarse-resolution climate models are a well-suited tool to investigate the recent intensification of rainfall in the {S}ahel, and may provide valuable information for climate change adaptation planning.},
  keywords = {{M}onsoons ; {R}ainfall ; {C}limate models ; {D}ecadal variability ; {T}rends ; {A}nthropogenic effects forcing ; afrique de l'ouest ; sahel},
  booktitle = {},
  journal = {{J}ournal of {C}limate},
  volume = {36},
  numero = {6},
  pages = {1823--1843},
  ISSN = {0894-8755},
  year = {2023},
  DOI = {10.1175/jcli-d-22-0412.1},
  URL = {https://www.documentation.ird.fr/hor/fdi:010087000},
}