@article{fdi:010085334,
  title = {{S}ub-seasonal forcing drives year-to-year variations of {S}outhern {O}cean primary productivity},
  author = {{P}rend, {C}. {J}. and {K}eerthi, {M}. {G}. and {L}evy, {M}arina and {A}umont, {O}livier and {G}ille, {S}. {T}. and {T}alley, {L}. {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{P}rimary productivity in the {S}outhern {O}cean plays a key role in global biogeochemical cycles. {W}hile much focus has been placed on phytoplankton production seasonality, non-seasonal fluctuations exceed the amplitude of the seasonal cycle across large swaths of the {A}ntarctic {C}ircumpolar {C}urrent. {T}his non-seasonal variability comprises a broad range of timescales from sub-seasonal (<3 months) to multi-annual (>1 year), all of which can project onto the annual mean value. {H}owever, year-to-year variations of surface chlorophyll ({SC}hl), a proxy for phytoplankton biomass, are typically attributed to ocean circulation changes associated with the {S}outhern {A}nnular {M}ode ({SAM}), which implicitly assumes that sub-seasonal variability averages to near-zero over long timescales. {H}ere, we test this assumption by applying a timeseries decomposition method to satellite-derived {SC}hl in order to separate the low-frequency and high-frequency contributions to the non-seasonal variability. {W}e find that throughout most of the {S}outhern {O}cean, year-to-year {SC}hl variations are dominated by the sub-seasonal component, which is not strongly correlated with the {SAM}. {T}he multi-annual component, while correlated with the {SAM}, only accounts for about 10% of the total {SC}hl variance. {T}his suggests that changes in annual mean {SC}hl are related to intermittent forcing at small scales, rather than low-frequency climate variability, and thus do not remain correlated over large regions.},
  keywords = {{OCEAN} {AUSTRAL}},
  booktitle = {},
  journal = {{G}lobal {B}iogeochemical {C}ycles},
  volume = {36},
  numero = {7},
  pages = {e2022{GB}007329 [15 p.]},
  ISSN = {0886-6236},
  year = {2022},
  DOI = {10.1029/2022gb007329},
  URL = {https://www.documentation.ird.fr/hor/fdi:010085334},
}