@article{fdi:010069407,
  title = {{P}ositive {I}ndian {O}cean {D}ipole events prevent anoxia off the west coast of {I}ndia},
  author = {{V}allivattathillam, {P}. and {I}yyappan, {S}. and {L}engaigne, {M}atthieu and {E}the, {C}. and {V}ialard, {J}{\'e}r{\^o}me and {L}evy, {M}arina and {S}uresh, {N}. and {A}umont, {O}livier and {R}esplandy, {L}. and {N}aik, {H}. and {N}aqvi, {W}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he seasonal upwelling along the west coast of {I}ndia ({WCI}) brings nutrient-rich, oxygen-poor subsurface waters to the continental shelf, favoring very low oxygen concentrations in the surface waters during late boreal summer and fall. {T}his yearly-recurring coastal hypoxia is more severe during some years, leading to coastal anoxia that has strong impacts on the living resources. {I}n the present study, we analyze a 1/4 degrees resolution coupled physical-biogeochemical regional oceanic simulation over the 1960-2012 period to investigate the physical processes influencing the oxycline interannual variability off the {WCI}, that being a proxy for the variability on the shelf in our model. {O}ur analysis indicates a tight relationship between the oxycline and thermocline variations in this region on both seasonal and interannual timescales, thereby revealing a strong physical control of the oxycline variability. {A}s in observations, our model exhibits a shallow oxycline and thermocline during fall that combines with interannual variations to create a window of opportunity for coastal anoxic events. {W}e further demonstrate that the boreal fall oxycline fluctuations off the {WCI} are strongly related to the {I}ndian {O}cean {D}ipole ({IOD}), with an asymmetric influence of its positive and negative phases. {P}ositive {IOD}s are associated with easterly wind anomalies near the southern tip of {I}ndia. {T}hese winds force downwelling coastal {K}elvin waves that propagate along the {WCI} and deepen the thermocline and oxycline there, thus preventing the occurrence of coastal anoxia. {O}n the other hand, negative {IOD}s are associated with {WCI} thermocline and oxycline anomalies of opposite sign but of smaller amplitude, so that the negative or neutral {IOD} phases are necessary but not the sufficient condition for coastal anoxia. {A}s the {IOD}s generally start developing in summer, these findings suggest some predictability to the occurrence of coastal anoxia off the {WCI} a couple of months ahead.},
  keywords = {{INDE} ; {OCEAN} {INDIEN}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {14},
  numero = {6},
  pages = {1541--1559},
  ISSN = {1726-4170},
  year = {2017},
  DOI = {10.5194/bg-14-1541-2017},
  URL = {https://www.documentation.ird.fr/hor/fdi:010069407},
}