@article{fdi:010064076,
  title = {{E}ffect of surface restoring on subsurface variability in a climate model during 1949-2005},
  author = {{R}ay, {S}. and {S}wingedouw, {D}. and {M}ignot, {J}uliette and {G}uilyardi, {E}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}nitializing the ocean for decadal predictability studies is a challenge, as it requires reconstructing the little observed subsurface trajectory of ocean variability. {I}n this study we explore to what extent surface nudging using well-observed sea surface temperature ({SST}) can reconstruct the deeper ocean variations for the 1949-2005 period. {A}n ensemble made with a nudged version of the {IPSLCM}5{A} model and compared to ocean reanalyses and reconstructed datasets. {T}he {SST} is restored to observations using a physically-based relaxation coefficient, in contrast to earlier studies, which use a much larger value. {T}he assessment is restricted to the regions where the ocean reanalyses agree, i. e. in the upper 500 m of the ocean, although this can be latitude and basin dependent. {S}ignificant reconstruction of the subsurface is achieved in specific regions, namely region of subduction in the subtropical {A}tlantic, below the thermocline in the equatorial {P}acific and, in some cases, in the {N}orth {A}tlantic deep convection regions. {B}eyond the mean correlations, ocean integrals are used to explore the time evolution of the correlation over 20-year windows. {C}lassical fixed depth heat content diagnostics do not exhibit any significant reconstruction between the different existing observation-based references and can therefore not be used to assess global average time-varying correlations in the nudged simulations. {U}sing the physically based average temperature above an isotherm (14 degrees {C}) alleviates this issue in the tropics and subtropics and shows significant reconstruction of these quantities in the nudged simulations for several decades. {T}his skill is attributed to the wind stress reconstruction in the tropics, as already demonstrated in a perfect model study using the same model. {T}hus, we also show here the robustness of this result in an historical and observational context.},
  keywords = {{D}ecadal climate prediction ; {I}nitial conditions ; {S}ubsurface reconstruction ; {S}urface nudging ; {MONDE}},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {44},
  numero = {9-10},
  pages = {2333--2349},
  ISSN = {0930-7575},
  year = {2015},
  DOI = {10.1007/s00382-014-2358-3},
  URL = {https://www.documentation.ird.fr/hor/fdi:010064076},
}