@article{fdi:010079837,
  title = {{D}eep eddy kinetic energy in the tropical {P}acific from {L}agrangian floats},
  author = {{D}elpech, {A}. and {C}ravatte, {S}ophie and {M}arin, {F}r{\'e}d{\'e}ric and {M}enesguen, {C}. and {M}orel, {Y}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}t the ocean surface, satellite observations have shown evidence of a large spectrum of waves at low latitudes. {H}owever, very little is known about the existence and properties of the deep variability. {M}ost of the subsurface observations rely on localized measurements, which do not allow for a global estimation of this variability. {I}n this study, we use velocity estimates, provided by {A}rgo float drifts at 1,000 m, to analyze the spatial and temporal distribution of the deep eddy kinetic energy ({EKE}) and its spectral signature with an unprecedented time and space coverage. {I}n the tropical {P}acific, high {EKE} is found along the equator, at the western boundary and poleward of 7 degrees {N}. {EKE} meridional distribution is also found to vary at the scale of the meridionally alternating mean zonal jets: it is higher inside eastward currents. {W}e develop an original statistical scale analysis to determine the temporal and spatial scale dependence of this deep {EKE} footprint. {W}e show the presence of periodic features whose characteristics are compatible with theoretical equatorial waves dispersion relations. {A}nnual and semiannual {R}ossby waves are observed at the equator, as well as similar to 30-day {Y}anai waves, consistent with surface tropical instability waves. {T}he location and intensification of these waves match the downward energy propagation predicted by ray tracing linear theory. {S}hort-scale variability (with similar to 70-day periods and 500-km wavelength) has also been detected poleward of 7 degrees {N}. {T}he generation mechanisms of this variability are discussed, as well as its potential importance for the mean circulation. {P}lain {L}anguage {S}ummary {E}nergy in the deep ocean is important as it is a potential driver of the deep circulation, which has important climate feedbacks. {B}ecause of its singular dynamics, the equatorial ocean is a preferential region of transfer of energy from the surface to the interior of the ocean. {V}ery little is known, however, about the energy content in the deep equatorial oceans. {I}n this study, we use the large number of floats, called {A}rgo floats, drifting at 1,000-m depth in the ocean to describe the deep kinetic energy in equatorial regions. {W}e show that various energetic waves are present at 1,000m in the tropical {P}acific, and we discuss their potential generation mechanisms as well as their implications for the circulation. {T}hese new observations may help to validate some theories or numerical simulations of the deep equatorial and tropical circulation.},
  keywords = {deep ocean ; equatorial and tropical ocean ; eddy kinetic energy ; equatorial waves ; {A}rgo floats ; {PACIFIQUE} ; {ZONE} {TROPICALE} ; {ZONE} {EQUATORIALE}},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch : {O}ceans},
  volume = {125},
  numero = {8},
  pages = {e2020{JC}016313 [23 p.]},
  ISSN = {2169-9275},
  year = {2020},
  DOI = {10.1029/2020jc016313},
  URL = {https://www.documentation.ird.fr/hor/fdi:010079837},
}