@article{fdi:010074109,
  title = {{N}orth {A}tlantic {O}cean internal decadal variability : role of the mean state and ocean-atmosphere coupling},
  author = {{G}astineau, {G}. and {M}ignot, {J}uliette and {A}rzel, {O}. and {H}uck, {T}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he origin of the decadal variability in the {N}orth {A}tlantic {O}cean is investigated in a series of coupled and ocean-only numerical experiments. {T}wo versions of the {IPSL}-{CM}5{A} model are considered, differing only by their atmospheric horizontal resolution (3.75 degrees x1.87 degrees and 2.5 degrees x1.25 degrees). {W}hen the ocean model is forced by the climatological surface fluxes from the low atmospheric resolution coupled model version, a 20-year variability emerges, similar to the variability found in the coupled simulation. {S}uch decadal variability is consistent with a large-scale baroclinic instability of the mean flow in the west {E}uropean basin. {I}ncreasing the atmospheric resolution leads to a more intense {I}celandic low, which intensifies the western subpolar gyre, and warms the eastern {N}orth {A}tlantic subpolar gyre region. {T}he mean state changes nearly vanish the associated internal oceanic variability under the corresponding climatological surface fluxes. {I}ncreasing the atmospheric resolution also produces a slightly weaker atmospheric stochastic forcing. {B}oth the mean state and atmospheric variability changes are consistent with the decreasing amplitude of the variability in the coupled model. {F}or both model versions, the amplitude of the internal oceanic variability is strongly enhanced in the presence of atmospheric stochastic forcing. {A}ir-sea coupling on the other hand has a moderate influence on the amplitude of the variability only in the low-resolution model version, where the {N}orth {A}tlantic oceanic variability at 20years increases by 23% due to coupling. {T}he coupling effect is therefore modest and sensitive to the atmospheric horizontal resolution.},
  keywords = {climate variability ; {A}tlantic {O}cean ; atmosphere-ocean general ; circulation models ; air-sea interactions ; {A}tlantic subpolar gyre ; {A}tlantic {M}eridional {O}verturning {C}irculation ; {ATLANTIQUE}},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch : {O}ceans},
  volume = {123},
  numero = {8},
  pages = {5949--5970},
  ISSN = {2169-9275},
  year = {2018},
  DOI = {10.1029/2018jc014074},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074109},
}