@article{fdi:010092739,
  title = {{O}n the intraseasonal oceanic processes constrained by data assimilation : a case study of the {T}ropical {P}acific},
  author = {{R}ohith, {B}. and {G}asparin, {F}lorent and {R}uggiero, {G}. and {R}emy, {E}. and {C}ravatte, {S}ophie},
  editor = {},
  language = {{ENG}},
  abstract = {{T}his study investigates the ability of a global ocean reanalysis at 1/12 degrees horizontal resolution, {GLORYS}12, to represent oceanic processes at intraseasonal and higher-frequency scales. {GLORYS}12, which includes data assimilation of satellite and multi-instrument in situ observations, is compared to a twin-free simulation (with no assimilation) in the tropical {P}acific {O}cean. {S}pectral analyses show that data assimilation improves the realism of sea surface height intraseasonal variability in the entire tropical {P}acific {O}cean, in both amplitude and phase, with an increase in the amplitude of more than 50% for the 20-90-day band and up to 15% for the 2-20-day band. {T}he improvement is largest along the 5 degrees {N}/{S} latitudes, where the magnitude of tropical instability waves is maximum, but is limited along the equator where steric height variability is dominated by intraseasonal oceanic {K}elvin waves, already well represented in the free simulation. {W}avenumber-frequency spectra show that data assimilation constraint improves both the spatial and temporal scales of intraseasonal waves and their timing. {D}ata assimilation impacts the realism of oceanic simulations in two ways. {B}y modifying the background oceanic stratification, it corrects the phase speed of westward-propagating waves. {I}t is also shown that the intraseasonal component of analysis increments (data assimilation corrections applied) is dynamically consistent and exhibits clear intraseasonal propagation. {B}y demonstrating the benefits of data assimilation for intraseasonal processes in the tropical {P}acific {O}cean, this study highlights the high value of both in situ and satellite observations to constrain ocean models in a wide range of time scales.},
  keywords = {{O}ceanic waves ; {P}lanetary waves ; {D}ata assimilation ; {O}cean models ; {I}ntraseasonal variability ; {PACIFIQUE} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{M}onthly {W}eather {R}eview},
  volume = {153},
  numero = {2},
  pages = {169--181},
  ISSN = {0027-0644},
  year = {2025},
  DOI = {10.1175/mwr-d-24-0027.1},
  URL = {https://www.documentation.ird.fr/hor/fdi:010092739},
}