@article{fdi:010074322,
  title = {{S}pectral signatures of the tropical {P}acific dynamics from model and altimetry : a focus on the meso-/submesoscale range},
  author = {{T}chilibou, {M}. and {G}ourdeau, {L}ionel and {M}orrow, {R}. and {S}{\'e}razin, {G}uillaume and {D}jath, {B}. and {L}yard, {F}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he processes that contribute to the flat sea surface height ({SSH}) wavenumber spectral slopes observed in the tropics by satellite altimetry are examined in the tropical {P}acific. {T}he tropical dynamics are first investigated with a 1/12 degrees global model. {T}he equatorial region from 10 degrees {N} to 10 degrees {S} is dominated by tropical instability waves with a peak of energy at 1000 km wavelength, strong anisotropy, and a cascade of energy from 600 km down to smaller scales. {T}he off-equatorial regions from 10 to 20 degrees latitude are characterized by a narrower mesoscale range, typical of midlatitudes. {I}n the tropics, the spectral taper window and segment lengths need to be adjusted to include these larger energetic scales. {T}he equatorial and off-equatorial regions of the 1/12 degrees model have surface kinetic energy spectra consistent with quasi-geostrophic turbulence. {T}he balanced component of the dynamics slightly flattens the {EKE} spectra, but modeled {SSH} wavenumber spectra maintain a steep slope that does not match the observed altimetric spectra. {A} second analysis is based on 1/36 degrees high-frequency regional simulations in the western tropical {P}acific, with and without explicit tides, where we find a strong signature of internal waves and internal tides that act to increase the smaller-scale {SSH} spectral energy power and flatten the {SSH} wavenumber spectra, in agreement with the altimetric spectra. {T}he coherent {M}2 baro-clinic tide is the dominant signal at similar to 140 km wavelength. {A}t short scales, wavenumber {SSH} spectra are dominated by incoherent internal tides and internal waves which extend up to 200 km in wavelength. {T}hese incoherent internal waves impact space scales observed by today's along-track altimetric {SSH}, and also on the future {S}urface {W}ater {O}cean {T}opography ({SWOT}) mission 2-{D} swath observations, raising the question of altimetric observability of the shorter mesoscale structures in the tropics.},
  keywords = {{PACIFIQUE} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{O}cean {S}cience},
  volume = {14},
  numero = {5},
  pages = {1283--1301},
  ISSN = {1812-0784},
  year = {2018},
  DOI = {10.5194/os-14-1283-2018},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074322},
}