@article{fdi:010062472,
  title = {{A}tmospheric response to sea-surface temperature in the eastern equatorial {A}tlantic at quasi-biweekly time-scales},
  author = {de {C}oetlogon, {G}. and {L}educ-{L}eballeur, {M}. and {M}eynadier, {R}. and {B}astin, {S}. and {D}iakhate, {M}. and {E}ymard, {L}aurence and {G}iordani, {H}. and {J}anicot, {S}erge and {L}azar, {A}lban},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he surface-wind response to sea-surface temperature ({SST}) and {SST} meridional gradient is investigated in the {G}ulf of {G}uinea by using daily observations and re-analyses in the 2000-2009 decade, with a focus on boreal spring and summer months ({M}ay to {A}ugust), where quasi-biweekly fluctuations in the position of the northern front of the equatorial cold tongue induce quasi-biweekly equatorial {SST} anomalies. {F}ollowing a large-scale wind acceleration (deceleration), an equatorial {SST} cold (warm) anomaly is created within a few days. {I}n order to explain the local atmospheric response to this {SST} anomaly, the two following mechanisms are invoked: first, a colder (warmer) ocean decreases (increases) the vertical stability in the marine atmospheric boundary layer, which favours a weaker (stronger) surface wind; and second, a negative (positive) anomaly of {SST} meridional gradient induces a positive (negative) anomaly of the sea-level-pressure meridional gradient, which decelerates (accelerates) the surface wind. {T}he first mechanism has an immediate effect in the equatorial belt between 1 degrees {S} and 1 degrees {N} (and to a lesser extent between 3 degrees {S} and 1 degrees {S}), whereas the second takes 1 or 2 days to adjust and damps anomalous southeasterlies up to 800 h{P}a in the low troposphere between 7 degrees {S} and 1 degrees {N}, through reversed anomalies of meridional {SST} and pressure gradient. {T}his negative feedback leads to weaker (stronger) winds in the southeastern tropical {A}tlantic, which forces the opposite phase of the oscillation within about 1 week. {A}round the {E}quator, where the amplitude of the oscillation is found to be maximal, both mechanisms combine to maximize the wind response to the front fluctuations. {B}etween the {E}quator and the coast, a low-level secondary atmospheric circulation takes control of the surface-wind acceleration or deceleration around 3 degrees {N}, which reduces the influence of the {SST}-front fluctuations.},
  keywords = {air-sea interaction ; intraseasonal variability ; eastern tropical ; {A}tlantic ; quasi-biweekly oscillation ; {SST} front ; {A}tlantic cold tongue ; {ATLANTIQUE} ; {ZONE} {EQUATORIALE}},
  booktitle = {},
  journal = {{Q}uarterly {J}ournal of the {R}oyal {M}eteorological {S}ociety},
  volume = {140},
  numero = {682},
  pages = {1700--1714},
  ISSN = {0035-9009},
  year = {2014},
  DOI = {10.1002/qj.2250},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062472},
}