@article{fdi:010074153,
  title = {{M}echanisms of the intensification of the upwelling-favorable winds during {E}l {N}ino 1997-1998 in the {P}eruvian upwelling system},
  author = {{C}hamorro, {A}. and {E}chevin, {V}incent and {C}olas, {F}ran{\c{c}}ois and {O}erder, {V}. and {T}am, {J}. and {Q}uispe-{C}calluari, {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he physical processes driving the wind intensification in a coastal band of similar to 100 km off {P}eru during the intense 1997-1998 {E}l {N}ino ({EN}) event were studied using a regional atmospheric model. {A} simulation performed for the period 1994-2000 reproduced the coastal wind response to local sea surface temperature ({SST}) forcing and large scale atmospheric conditions. {T}he model, evaluated with satellite data, represented well the intensity, seasonal and interannual variability of alongshore (i.e. {NW}-{SE}) winds. {A}n alongshore momentum budget showed that the pressure gradient was the dominant force driving the surface wind acceleration. {T}he pressure gradient tended to accelerate the coastal wind, while turbulent vertical mixing decelerated it. {A} quasi-linear relation between surface wind and pressure gradient anomalies was found. {A}longshore pressure gradient anomalies were caused by a greater increase in near-surface air temperature off the northern coast than off the southern coast, associated with the inhomogeneous {SST} warming. {V}ertical profiles of wind, mixing coefficient, and momentum trends showed that the surface wind intensification was not caused by the increase of turbulence in the planetary boundary layer. {M}oreover, the temperature inversion in the vertical mitigated the development of pressure gradient due to air convection during part of the event. {S}ensitivity experiments allowed to isolate the respective impacts of the local {SST} forcing and large scale condition on the coastal wind intensification. {I}t was primarily driven by the local {SST} forcing whereas large scale variability associated with the {S}outh {P}acific {A}nticyclone modulated its effects. {E}xamination of other {EN} events using reanalysis data confirmed that intensifications of alongshore wind off {P}eru were associated with {SST} alongshore gradient anomalies, as during the 1997-1998 event.},
  keywords = {{O}cean-atmosphere interactions ; {C}oastal winds ; {E}l {N}ino 1997/1998 ; {P}eruvian upwelling system ; {PEROU} ; {PACIFIQUE}},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {51},
  numero = {9-10},
  pages = {3717--3733},
  ISSN = {0930-7575},
  year = {2018},
  DOI = {10.1007/s00382-018-4106-6},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074153},
}