@article{fdi:010084500,
  title = {{B}ridging the gaps between particulate backscattering measurements and modeled particulate organic carbon in the ocean},
  author = {{G}ali, {M}. and {F}alls, {M}. and {C}laustre, {H}. and {A}umont, {O}livier and {B}ernardello, {R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{O}ceanic particulate organic carbon ({POC}) is a small but dynamic component of the global carbon cycle. {B}iogeochemical models historically focused on reproducing the sinking flux of {POC} driven by large fast-sinking particles ({LPOC}). {H}owever, suspended and slow-sinking particles ({SPOC}, here < 100 mu m) dominate the total {POC} ({TPOC}) stock, support a large fraction of microbial respiration, and can make sizable contributions to vertical fluxes. {R}ecent developments in the parameterization of {POC} reactivity in {PISCES} ({P}elagic {I}nteractions {S}cheme for {C}arbon and {E}cosystem {S}tudies model; {PISCES}v2_{RC}) have improved its ability to capture {POC} dynamics. {H}ere we evaluated this model by matching a global 3{D} simulation and 1{D} simulations at 50 different locations with observations made from biogeochemical ({BGC}-) {A}rgo floats and satellites. {O}ur evaluation covers globally representative biomes between 0 and 1000 m depth and relies on (1) a refined scheme for converting particulate backscattering at 700 nm (b(bp)(700)) to {POC}, based on biome-dependent {POC} / b(bp)(700) ratios in the surface layer that decrease to an asymptotic value at depth; (2) a novel approach for matching annual time series of {BGC}-{A}rgo vertical profiles to {PISCES} 1{D} simulations forced by pre-computed vertical mixing fields; and (3) a critical evaluation of the correspondence between in situ measurements of {POC} fractions, {PISCES} model tracers, and {SPOC} and {LPOC} estimated from high vertical resolution b(bp)(700) profiles through a separation of the baseline and spike signals. {W}e show that {PISCES} captures the major features of {SPOC} and {LPOC} across a range of spatiotemporal scales, from highly resolved profile time series to biome-aggregated climatological profiles. {M}odel-observation agreement is usually better in the epipelagic (0-200 m) than in the mesopelagic (200-1000 m), with {SPOC} showing overall higher spatiotemporal correlation and smaller deviation (typically within a factor of 1.5). {S}till, annual mean {LPOC} stocks estimated from {PISCES} and {BGC}-{A}rgo are highly correlated across biomes, especially in the epipelagic (r = 0.78; n = 50). {E}stimates of the {SPOC} / {TPOC} fraction converge around a median of 85 % (range 66 %-92 %) globally. {D}istinct patterns of model-observations misfits are found in subpolar and subtropical gyres, pointing to the need to better resolve the interplay between sinking, remineralization, and {SPOC}-{LPOC} interconversion in {PISCES}. {O}ur analysis also indicates that a widely used satellite algorithm overestimates {POC} severalfold at high latitudes during the winter. {T}he approaches proposed here can help constrain the stocks, and ultimately budgets, of oceanic {POC}.},
  keywords = {{MONDE}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {19},
  numero = {4},
  pages = {1245--1275},
  ISSN = {1726-4170},
  year = {2022},
  DOI = {10.5194/bg-19-1245-2022},
  URL = {https://www.documentation.ird.fr/hor/fdi:010084500},
}