@article{fdi:010096043,
  title = {{T}ropical salinity contrast strengthening in {CMIP}6 : inter-model diversity and mechanisms},
  author = {{P}ang, {S}. {S}. and {V}ialard, {J}{\'e}r{\^o}me and {L}engaigne, {M}atthieu and {W}ang, {X}. {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e analyze projected tropical sea surface salinity ({SSS}) changes in 32 {CMIP}6 models' historical and {SSP}5-8.5 scenario simulations, examining both the multi-model mean ({MMM}) and inter-model diversity. {B}y 2100, {MMM} inter-basin contrasts strengthen, with freshening in the tropical {I}ndian {O}cean ({TIO}) and equatorial-northern {P}acific ({ENPO}), and saltening in the southern {P}acific ({SPO}) and tropical {A}tlantic ({TAO}). {B}asin-scale future {SSS} changes are primarily driven by surface freshwater fluxes, with lateral advection redistributing anomalies within each basin. {P}recipitation dominates the freshwater flux changes, except in the tropical {A}tlantic where evaporation plays a key role. {T}wo uncorrelated indices, contrasting {SPO} versus {TIO} and {TAO} versus {ENPO}, explain 76% of the variance across models. {P}hysically, stronger relative warming of the {N}orthern {H}emisphere enhances rainfall over the {TIO} monsoon region (freshening) while suppressing rainfall along the {S}outh {P}acific {C}onvergence {Z}one (saltening). {T}he increasing {TAO}-{ENPO} contrast arises from two distinct mechanisms: in the {P}acific, an enhanced {E}l {N}iño-like warming pattern reduces atmospheric stability, intensifying rainfall and freshening {ENPO}; in the {A}tlantic, saltening reflects stronger evaporation under warmer conditions, though at a weaker rate than predicted by {C}lausius-{C}lapeyron scaling (4.2 vs. 7% ). {P}revious studies linked strengthening of inter-basin salinity gradients to a thermodynamically intensified hydrological cycle. {O}ur analysis highlights a more nuanced picture: {A}tlantic saltening reflects this thermodynamic control, while {SSS} changes elsewhere are mainly driven by atmospheric circulation and rainfall changes tied to uneven {SST} warming. {T}he {CMIP}6 statistical analyses highlight dynamical mechanisms that motivate further testing through targeted ocean simulations.},
  keywords = {{MONDE}},
  booktitle = {},
  journal = {{E}arths {F}uture},
  volume = {14},
  numero = {1},
  pages = {e2025{EF}007346 [16 p.]},
  year = {2026},
  DOI = {10.1029/2025ef007346},
  URL = {https://www.documentation.ird.fr/hor/fdi:010096043},
}