@article{fdi:010066756,
  title = {{A} simple estimation of equatorial {P}acific response from windstress to untangle {I}ndian {O}cean {D}ipole and {B}asin influences on {E}l {N}ino},
  author = {{I}zumo, {T}akeshi and {V}ialard, {J}{\'e}r{\^o}me and {D}ayan, {H}. and {L}engaigne, {M}atthieu and {S}uresh, {I}.},
  editor = {},
  language = {{ENG}},
  abstract = {{S}ea {S}urface {T}emperature ({SST}) anomalies that develop in spring in the central {P}acific are crucial to the {E}l {N}io {S}outhern {O}scillation ({ENSO}) development. {H}ere we use a linear, continuously stratified, ocean model, and its impulse response to a typical {ENSO} wind pattern, to derive a simple equation that relates those {SST} anomalies to the low frequency evolution of zonal wind stress anomalies tau (x) over the preceding months. {W}e show that {SST} anomalies can be approximated as a "causal" filter of tau (x) , tau (x) (t - t (1)) - c tau (x) (t - t (2)), where t(1) is similar to 1-2 months, t(2) - t(1) is similar to 6 months and c ranges between 0 and 1 depending on tau (x) location (i.e. {SST} anomalies are approximately proportional to the wind stress anomalies 1-2 months earlier minus a fraction of the wind stress anomalies 7-8 months earlier). {T}he first term represents the fast oceanic response, while the second one represents the delayed negative feedback associated with wave reflection at both boundaries. {T}his simple approach is then applied to assess the relative influence of the {I}ndian {O}cean {D}ipole ({IOD}) and of the {I}ndian {O}cean {B}asin-wide warming/cooling ({IOB}) in favouring the phase transition of {ENSO}. {I}n agreement with previous studies, {A}tmospheric {G}eneral {C}irculation {M}odel experiments indicate that the equatorial {P}acific wind responses to the {IOD} eastern and ({IOB}-related) western poles tend to cancel out during autumn. {T}he abrupt demise of the {IOD} eastern pole thus favours an abrupt development of the {IOB}-cooling-forced westerly wind anomalies in the western {P}acific in winter-spring (vice versa for an {IOB} warming). {A}s expected from the simple {SST} equation above, the faster wind change fostered by the {IOD} enhances the central {P}acific {SST} response as compared to the sole {IOB} influence. {T}he {IOD} thereby enhances the {IOB} tendency to favour {ENSO} phase transition. {A}s the {IOD} is more independent of {ENSO} than the {IOB}, this external influence could contribute to enhanced {ENSO} predictability.},
  keywords = {{E}l {N}ino {S}outhern {O}scillation ({ENSO}) ; {E}quatorial {P}acific {O}cean dynamics ; {C}onvolution to impulse response of a linear system ; {A}tmospheric teleconnections ; {I}ndian {O}cean {D}ipole mode ({IOD}) and {B}asin-wide warming/cooling ({IOB}) ; {L}inear {C}ontinuously {S}tratified model ({LCS}) ; {PACIFIQUE} ; {OCEAN} {INDIEN}},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {46},
  numero = {7-8},
  pages = {2247--2268},
  ISSN = {0930-7575},
  year = {2016},
  DOI = {10.1007/s00382-015-2700-4},
  URL = {https://www.documentation.ird.fr/hor/fdi:010066756},
}