@article{fdi:010087680,
  title = {{H}ow does the phytoplankton-light feedback affect the marine {N}2{O} inventory ?},
  author = {{B}erthet, {S}. and {J}ouanno, {J}ulien and {S}eferian, {R}. and {G}ehlen, {M}. and {L}lovel, {W}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he phytoplankton-light feedback ({PLF}) describes the interaction between phytoplankton biomass and the downwelling shortwave radiation entering the ocean. {T}he {PLF} allows the simulation of differential heating across the ocean water column as a function of phytoplankton concentration. {O}nly one third of the {E}arth system models contributing to the 6th phase of the {C}oupled {M}odel {I}ntercomparison {P}roject ({CMIP}6) include a complete representation of the {PLF}. {I}n other models, the {PLF} is either approximated by a prescribed climatology of chlorophyll or not represented at all. {C}onsequences of an incomplete representation of the {PLF} on the modelled biogeochemical state have not yet been fully assessed and remain a source of multi-model uncertainty in future projection. {H}ere, we evaluate within a coherent modelling framework how representations of the {PLF} of varying complexity impact ocean physics and ultimately marine production of nitrous oxide ({N}2{O}), a major greenhouse gas. {W}e exploit global sensitivity simulations at 1 circle horizontal resolution over the last 2 decades (1999-2018), coupling ocean, sea ice and marine biogeochemistry. {T}he representation of the {PLF} impacts ocean heat uptake and temperature of the first 300 m of the tropical ocean. {T}emperature anomalies due to an incomplete {PLF} representation drive perturbations of ocean stratification, dynamics and oxygen concentration. {T}hese perturbations translate into different projection pathways for {N}2{O} production depending on the choice of the {PLF} representation. {T}he oxygen concentration in the {N}orth {P}acific oxygen-minimum zone is overestimated in model runs with an incomplete representation of the {PLF}, which results in an underestimation of local {N}2{O} production. {T}his leads to important regional differences of sea-to-air {N}2{O} fluxes: fluxes are enhanced by up to 24 % in the {S}outh {P}acific and {S}outh {A}tlantic subtropical gyres but reduced by up to 12 % in oxygen-minimum zones of the {N}orthern {H}emisphere. {O}ur results, based on a global ocean-biogeochemical model at {CMIP}6 state-of-the-art level, shed light on current uncertainties in modelled marine nitrous oxide budgets in climate models.},
  keywords = {{MONDE}},
  booktitle = {},
  journal = {{E}arth {S}ystem {D}ynamics},
  volume = {14},
  numero = {2},
  pages = {399--412},
  ISSN = {2190-4979},
  year = {2023},
  DOI = {10.5194/esd-14-399-2023},
  URL = {https://www.documentation.ird.fr/hor/fdi:010087680},
}