@article{fdi:010047447,
  title = {{T}riggering of {E}l {N}ino by westerly wind events in a coupled general circulation model},
  author = {{L}engaigne, {M}. and {G}uilyardi, {E}. and {B}oulanger, {J}ean-{P}hilippe and {M}enk{\`e}s, {C}hristophe and {D}elecluse, {P}. and {I}nness, {P}. and {C}ole, {J}. and {S}lingo, {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}wo ten-members ensemble experiments using a coupled ocean-atmosphere general circulation model are performed to study the dynamical response to a strong westerly wind event ({WWE}) when the tropical {P}acific has initial conditions favourable to the development of a warm event. {I}n the reference ensemble ({CREF}), no wind perturbation is introduced, whereas a strong westerly wind event anomaly is introduced in boreal winter over the western {P}acific in the perturbed ensemble ({CWWE}). {O}ur results demonstrate that an intense {WWE} is capable of establishing the conditions under which a strong {E}l {N}ino event can occur. {F}irst, it generates a strong downwelling {K}elvin wave that generates a positive sea surface temperature ({SST}) anomaly in the central-eastern {P}acific amplified through a coupled ocean-atmosphere interaction. {T}his anomaly can be as large as 2.5degrees{C} 60 days after the {WWE}. {S}econdly, this {WWE} also initiates an eastward displacement of the warm-pool that promotes the occurrence of subsequent {WWE}s in the following months. {T}hese events reinforce the initial warming through the generation of additional {K}elvin waves and generate intense surface jets at the eastern edge of the warm-pool that act to further shift warm waters eastward. {T}he use of a ten-members ensemble however reveals substantial differences in the coupled response to a {WWE}. {W}hereas four members of {CWWE} ensemble develop into intense {E}l {N}ino warming as described above, four others display a moderate warming and two remains in neutral conditions. {T}his diversity between the members appears to be due to the internal atmospheric variability during and following the inserted {WWE}. {I}n the four moderate warm cases, the warm-pool is initially shifted eastward following the inserted {WWE}, but the subsequent weak {WWE} activity ( when compared to the strong warming cases) prevents to further shift the warm-pool eastwards. {T}he seasonal strengthening of trade winds in {J}une - {J}uly can therefore act to shift warm waters back into the western {P}acific, reducing the central-eastern {P}acific warming. {T}his strong sensitivity of the coupled response to {WWE}s may therefore limit the predictability of {E}l {N}ino events, as the high frequency wind variability over the warm pool region remains largely unpredictable even at short time lead.},
  keywords = {},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {23},
  numero = {6},
  pages = {601--620},
  ISSN = {0930-7575},
  year = {2004},
  DOI = {10.1007/s00382-004-0457-2},
  URL = {https://www.documentation.ird.fr/hor/fdi:010047447},
}