@article{fdi:010069280,
  title = {{W}est {A}frican monsoon dynamics and precipitation: the competition between global {SST} warming and {CO}2 increase in {CMIP}5 idealized simulations},
  author = {{G}aetani, {M}. and {F}lamant, {C}. and {B}astin, {S}. and {J}anicot, {S}erge and {L}avaysse, {C}. and {H}ourdin, {F}. and {B}raconnot, {P}. and {B}ony, {S}.},
  editor = {},
  language = {{ENG}},
  abstract = {{C}limate variability associated with the {W}est {A}frican monsoon ({WAM}) has important environmental and socio-economic impacts in the region. {H}owever, state-of-the-art climate models still struggle in producing reliable climate predictions. {A}n important cause of this low predictive skill is the sensitivity of climate models to different forcings. {I}n this study, the mechanisms linking the {WAM} dynamics to the {CO}2 forcing are investigated, by comparing the effect of the {CO}2 direct radiative effect with its indirect effect mediated by the global sea surface warming. {T}he {J}uly-to-{S}eptember {WAM} variability is studied in climate simulations extracted from the {C}oupled {M}odel {I}ntercomparison {P}roject {P}hase 5 archive, driven by prescribed sea surface temperature ({SST}). {T}he individual roles of global {SST} warming and {CO}2 atmospheric concentration increase are investigated through idealized experiments simulating a 4 {K} warmer {SST} and a quadrupled {CO}2 concentration, respectively. {R}esults show opposite and competing responses in the {WAM} dynamics and precipitation. {A} dry response (-0.6 mm/day) to the {SST} warming is simulated in the {S}ahel, with dryer conditions over western {S}ahel (-0.8 mm/day). {C}onversely, the {CO}2 increase produces wet conditions (+0.5 mm/day) in the {S}ahel, with the strongest response over central-eastern {S}ahel (+0.7 mm/day). {T}he associated responses in the atmospheric dynamics are also analysed, showing that the {SST} warming affects the {S}ahelian precipitation through modifications in the global tropical atmospheric dynamics, reducing the importance of the regional drivers, while the {CO}2 increase reinforces the coupling between precipitation and regional dynamics. {A} general agreement in model responses demonstrates the robustness of the identified mechanisms linking the {WAM} dynamics to the {CO}2 direct and indirect forcing, and indicates that these primary mechanisms are captured by climate models. {R}esults also suggest that the spread in future projections may be caused by unbalanced model responses to the {CO}2 direct and indirect forcing.},
  keywords = {{W}est {A}frica ; {S}ahel ; {M}onsoon ; {P}recipitation ; {S}ahara ; {CO}2 ; {SST} ; {G}lobal ; warming ; {C}limate modelling ; {CMIP}5 ; {AFRIQUE} {DE} {L}'{OUEST} ; {SAHEL} ; {SAHARA}},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {48},
  numero = {3-4},
  pages = {1353--1373},
  ISSN = {0930-7575},
  year = {2017},
  DOI = {10.1007/s00382-016-3146-z},
  URL = {https://www.documentation.ird.fr/hor/fdi:010069280},
}