@article{fdi:010080977,
  title = {{C}ontributions of internal variability and external forcing to the recent trends in the {S}outheastern {P}acific and {P}eru-{C}hile upwelling system},
  author = {{J}ebri, {B}. and {K}hodri, {M}yriam and {E}chevin, {V}incent and {G}astineau, {G}. and {T}hiria, {S}. and {V}ialard, {J}{\'e}r{\^o}me and {L}ebas, {N}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n a warming world context, sea surface temperature ({SST}) off central-south {P}eru, northern {C}hile, and farther offshore increases at a slower rate than the global average since several decades (i.e., cools, relative to the global average). {T}his tendency is synchronous with an interdecadal {P}acific oscillation ({IPO}) negative trend since similar to 1980, which has a cooling signature in the southeastern {P}acific. {H}ere, we use a large ensemble of historical coupled model simulations to investigate the relative roles of internal variability (and in particular the {IPO}) and external forcing in driving this relative regional cooling, and the associated mechanisms. {T}he ensemble mean reproduces the relative cooling, in response to an externally forced southerly wind anomaly, which strengthens the upwelling off {C}hile in recent decades. {T}his southerly wind anomaly results from the poleward expansion of the {S}outhern {H}emisphere {H}adley cell. {A}ttribution experiments reveal that this poleward expansion and the resulting enhanced upwelling mostly occur in response to increasing greenhouse gases and stratospheric ozone depletion since similar to 1980. {A}n oceanic heat budget confirms that the wind-forced upwelling enhancement dominates the relative cooling near the coast. {I}n contrast, a wind-forced deepening of the mixed layer drives the offshore cooling. {W}hile internal variability contributes to the spread of tendencies, the ensemble-mean relative cooling in the southeastern {P}acific is consistent with observations and occurs irrespectively of the {IPO} phase, hence, indicating the preeminent role of external forcing.},
  keywords = {{PACIFIQUE} ; {PEROU} ; {CHILI}},
  booktitle = {},
  journal = {{J}ournal of {C}limate},
  volume = {33},
  numero = {24},
  pages = {10555--10578},
  ISSN = {0894-8755},
  year = {2020},
  DOI = {10.1175/jcli-d-19-0304.1},
  URL = {https://www.documentation.ird.fr/hor/fdi:010080977},
}