@article{fdi:010086919,
  title = {{I}mproving and harmonizing {E}l {N}ino recharge indices},
  author = {{I}zumo, {T}akeshi and {C}olin, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{E}l {N}ino {S}outhern {O}scillation ({ENSO}) is the leading mode of interannual climate variability, with large socioeconomical and environmental impacts. {T}he main conceptual model for {ENSO}, the {R}echarge {O}scillator ({RO}), considers two independent modes: the fast zonal tilt mode in phase with central-eastern {P}acific {T}emperature ({T}-e), and the slow recharge mode in phase quadrature. {H}owever, usual indices (western or equatorial sea level/thermocline depth h) do not orthogonally isolate the slow recharge mode, leaving it correlated with {T}-e. {F}urthermore the optimal index is currently debated. {H}ere, we develop an improved recharge index by objectively optimizing the {RO} equations fit to observations. (a) {T}-e-variability is regressed out, to build h(ind) statistically-independent from {T}-e. {C}apturing the pure recharge, h(ind) reconciles usual indices. (b) {T}he optimum is equatorial plus southwestern {P}acific h(ind_eq+sw) (because of {ENSO} {E}kman pumping meridional asymmetry). {U}sing h(ind_eq+sw), the {RO} becomes more consistent with observations. h(ind_eq+sw) is more relevant for {ENSO} operational diagnostics.},
  keywords = {{E}l {N}ino {S}outhern {O}scillation ({ENSO}) ; oceanic metrics for {R}echarge ; {O}scillator conceptual model ; seasonal climate and ocean forecast and ; operational diagnostics ; {ENSO} simple models ; warm water volume ({WWV}) ; optimisation ; equatorial and south west tropical {P}acific ; {PACIFIQUE} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{G}eophysical {R}esearch {L}etters},
  volume = {49},
  numero = {23},
  pages = {e2022{GL}101003 [10 p.]},
  ISSN = {0094-8276},
  year = {2022},
  DOI = {10.1029/2022gl101003},
  URL = {https://www.documentation.ird.fr/hor/fdi:010086919},
}