@article{fdi:010088945,
  title = {{I}nterhemispheric temperature gradient and {E}quatorial {P}acific {SST}s drive {S}ahel {M}onsoon uncertainties under global warming},
  author = {{G}uilbert, {M}. and {T}erray, {P}ascal and {M}ignot, {J}uliette and {O}llier, {L}. and {G}astineau, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {S}ahel is one of the most vulnerable regions to climate change. {R}obust estimation of future changes in the {S}ahel monsoon is therefore essential for effective climate change adaptation. {U}nfortunately, state-of-the-art climate models show large uncertainties in their projections of {S}ahel rainfall. {I}n this study, we use 32 models from {CMIP}6 to iden-tify the sources of this large intermodel spread of {S}ahel rainfall. {B}y using maximum covariance analysis, we first highlight two new key drivers of this spread during boreal summer: the interhemispheric temperature gradient and equatorial {P}acific sea surface temperature ({SST}) changes. {T}his contrasts with previous studies, which have focused mainly on the {N}orthern {H}emisphere rather than the global scale, and in which the {P}acific {O}cean has been neglected in favor of the {A}tlantic. {N}ext, we unravel the physical mechanisms behind these statistical relationships. {F}irst, the modulation of the interhemispheric temperature gradient across the models leads to varying latitudinal positions of the intertropical convergence zone and, consequently, varying {S}ahel rainfall intensity. {S}econd, models that exhibit less warming than the multimodel mean in the equatorial {P}acific, thereby projecting a less "{E}l {N}ino-like" mean state, simulate enhanced precipitation over the central {S}ahel in the future through modulations of the {W}alker circulation, the tropical easterly jet, the meridional tropospheric temperature gradient, and hence regional zonal wind shear. {F}inally, we show that these two indices collectively explain 62% of {S}ahel rainfall change uncertainty: 40% due to the interhemispheric temperature gradient and 22% through equato-rial {P}acific {SST}.},
  keywords = {{T}eleconnections ; {M}onsoons ; {C}limate change ; {U}ncertainty ; {SAHEL} ; {PACIFIQUE} ; {ZONE} {EQUATORIALE}},
  booktitle = {},
  journal = {{J}ournal of {C}limate},
  volume = {37},
  numero = {3},
  pages = {1033--1052},
  ISSN = {0894-8755},
  year = {2024},
  DOI = {10.1175/jcli-d-23-0162.1},
  URL = {https://www.documentation.ird.fr/hor/fdi:010088945},
}