@article{PAR00025262,
  title = {{O}n the detection of externally forced decadal modulations of the {S}ahel rainfall over the whole {T}wentieth {C}entury in the {CMIP}6 ensemble},
  author = {{N}diaye, {C}. {D}. and {M}ohino, {E}. and {M}ignot, {J}uliette and {S}all, {S}. {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {S}ahel semiarid region was marked during the twentieth century by significant modulations of its rainfall regime at the decadal time scale. {P}art of these modulations have been associated with the internal variability of the climate system, linked to changes in oceanic sea surface temperature. {M}ore recently, several studies have highlighted the influence of external forcings during the dry period in the 1980s and the recovery around the 2000s. {I}n this work we evaluate the internally and externally driven decadal modulations of {S}ahel rainfall during the entire twentieth century using a set of 12 models from phase 6 of the {C}oupled {M}odel {I}ntercomparison {P}roject ({CMIP}6). {W}e begin by proposing a physically based definition of {S}ahel rainfall that takes into account the southward bias in the location of the {S}ahelian {ITCZ} simulated by all the models. {O}ur results show that the amplitude of the decadal variability, which is underestimated by most models, is mainly produced by the internally driven component. {C}onversely, the external forcing tends to enhance the synchrony of the simulated and observed decadal modulations in most models, providing statistically significant correlations of the historical ensemble mean with observations in 1/3 of the models, namely {IPSL}-{CM}6{A}-{LR}, {INM}-{CM}5-0, {MRI}-{ESM}2-0, and {GISS}-{E}2-1-{G}. {F}urther analysis of the detection and attribution runs of the {IPSL}-{CM}6{A}-{LR} shows that anthropogenic aerosol dominate the decadal modulations of {S}ahel rainfall simulated by this model, suggesting that at least a part of the impact is ocean-mediated and operated through shifts in the {ITCZ} and the {S}aharan heat low.},
  keywords = {{M}onsoons ; {A}nthropogenic effects ; forcing ; {C}oupled models ; {I}nternal variability ; {D}ecadal variability ; {T}ropical variability ; {SAHEL}},
  booktitle = {},
  journal = {{J}ournal of {C}limate},
  volume = {35},
  numero = {21},
  pages = {3339--3354},
  ISSN = {0894-8755},
  year = {2022},
  DOI = {10.1175/jcli-d-21-0585.1},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00025262},
}