@article{fdi:010081438,
  title = {{S}easonal and intraseasonal biogeochemical variability in the thermocline ridge of the southern tropical {I}ndian {O}cean},
  author = {{R}esplandy, {L}. and {V}ialard, {J}{\'e}r{\^o}me and {L}{\'e}vy, {M}. and {A}umont, {O}livier and {D}andonneau, {Y}ves},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {S}ea-viewing {W}ide {F}ield-of-view {S}ensor ({S}ea{W}i{FS}) time series shows high variability of surface chlorophyll at seasonal and intraseasonal time scales in the oligotrophic southern tropical {I}ndian {O}cean thermocline ridge called the {S}eychelles-{C}hagos thermocline ridge ({SCTR}). {T}he {SCTR} is characterized by an open ocean upwelling due to local {E}kman pumping, which annually maintains the mixed layer ({ML}) shallow and is responsive to atmospheric forcing and in particular to the {M}adden-{J}ulian {O}scillation ({MJO}) at an intraseasonal time scale. {H}ere we present an overview of {SCTR} biogeochemistry and investigate the physical processes driving the response observed at seasonal and intraseasonal time scales. {U}sing satellite observations and biophysical ocean simulations, we show that seasonal and intraseasonal {S}ea{W}i{FS} signals (in austral winter and during {MJO} events, respectively) correspond to wind-induced mixing episodes. {D}uring such episodes, entrainment fertilizes the {ML} and allows phytoplankton production. {I}ncreased surface production is compensated by a decrease in the subsurface due to light limitation, leading to no significant change in integrated biomass and carbon export. {S}atellite observations and model results support the conclusion that the biogeochemical response to {MJO} is highly dependent on interannual variability of thermocline depth. {F}ollowing {I}ndian {O}cean {D}ipole events, deepened nutrient-rich waters prevent nutrient input into the {ML}, decreasing the biogeochemical response to {MJO}. {T}hese results shed light on the physical processes at work in the strong surface temperature response to {MJO} in this region and suggest that entrainment cooling can play a role in the temperature signature to the {MJO} but is highly modulated by basin-scale interannual variability.},
  keywords = {{OCEAN} {INDIEN}},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch - {O}ceans},
  volume = {114},
  numero = {},
  pages = {{C}07024},
  ISSN = {0148-0227},
  year = {2009},
  DOI = {10.1029/2008jc005246},
  URL = {https://www.documentation.ird.fr/hor/fdi:010081438},
}