@article{fdi:010049690,
  title = {{R}ole of the upper ocean structure in the response of {ENSO}-like {SST} variability to global warming},
  author = {{Y}eh, {S}. {W}. and {D}ewitte, {B}oris and {Y}im, {B}. {Y}. and {N}oh, {Y}.},
  editor = {},
  language = {{FRE}},
  abstract = {{T}he response of {E}l {N}ino and {S}outhern {O}scillation ({ENSO})-like variability to global warming varies comparatively between the two different climate system models, i.e., the {M}eteorological {R}esearch {I}nstitute ({MRI}) and {G}eophysical {F}luid {D}ynamics {L}aboratory ({GFDL}) {C}oupled {G}eneral {C}irculation {M}odels ({CGCM}s). {H}ere, we examine the role of the simulated upper ocean temperature structure in the different sensitivities of the simulated {ENSO} variability in the models based on the different level of {CO}2 concentrations. {I}n the {MRI} model, the sea surface temperature ({SST}) undergoes a rather drastic modification, namely a tendency toward a permanent {E}l {N}ino-like state. {T}his is associated with an enhanced stratification which results in greater {ENSO} amplitude for the {MRI} model. {O}n the other hand, the {ENSO} simulated by {GFDL} model is hardly modified although the mean temperature in the near surface layer increases. {I}n order to understand the associated mechanisms we carry out a vertical mode decomposition of the mean equatorial stratification and a simplified heat balance analysis using an intermediate tropical {P}acific model tuned from the {CGCM} outputs. {I}t is found that in the {MRI} model the increased stratification is associated with an enhancement of the zonal advective feedback and the non-linear advection. {I}n the {GFDL} model, on the other hand, the thermocline variability and associated anomalous vertical advection are reduced in the eastern equatorial {P}acific under global warming, which erodes the thermocline feedback and explains why the {ENSO} amplitude is reduced in a warmer climate in this model. {I}t is suggested that change in stratification associated with global warming impacts the equatorial wave dynamics in a way that enhances the second baroclinic mode over the gravest one, which leads to the change in feedback processes in the {CGCM}s. {O}ur results illustrate that the upper ocean vertical structure simulated in the {CGCM}s is a key parameter of the sensitivity of {ENSO}-like {SST} variability to global warming.},
  keywords = {},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {35},
  numero = {2-3},
  pages = {355--369},
  ISSN = {0930-7575},
  year = {2010},
  DOI = {10.1007/s00382-010-0849-4},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049690},
}