FN Archimer Export Format PT J TI Quantifying observational errors in Biogeochemical‐Argo oxygen, nitrate and chlorophyll a concentrations BT AF MIGNOT, A D'ORTENZIO, F TAILLANDIER, V COSSARINI, G SALON, S AS 1:1;2:1;3:1;4:2;5:2; FF 1:;2:;3:;4:;5:; C1 Sorbonne Universités, UPMC Univ. Paris 06, CNRS, UMR 7093, Laboratoire d’Océanographie de Villefranche (LOV), 181 Chemin du Lazaret, 06230 Villefranche-sur-mer, France. Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Borgo Grotta Gigante 42/c, 34010 Sgonico (TS), Italy C2 UNIV PARIS 06, FRANCE INGV, ITALY IF 4.497 TC 17 UR https://archimer.ifremer.fr/doc/00486/59745/62845.pdf https://archimer.ifremer.fr/doc/00486/59745/62846.pdf LA English DT Article CR BIO-ARGO-MED-2015 BO Téthys II AB BGC‐Argo floats observations are becoming a major data source for assimilation into and constraining of ocean biogeochemical models. An important prerequisite for a successful synthesis between models and observations is the characterization of the observational errors in BGC‐Argo float data. The root‐mean‐squared error, multiplicative and additive biases in quality‐controlled data sets of oxygen, nitrate and chlorophyll a concentrations collected with 17 BGC‐Argo floats in the Mediterranean Sea between 2013 and 2017 are assessed using the triple collocation analysis. The analysis suggests that BGC‐Argo float oxygen, nitrate and chlorophyll a data suffer from an additive bias of 2.9± 5.5 μmol kg‐1, 0.46± 0.07 μmol kg‐1 and ‐0.06 ± 0.02 mg m‐3, respectively. The root‐mean‐squared error is evaluated at 5.1 ± 0.8 μmol kg‐1, 0.25 ± 0.07 μmol kg‐1 and 0.03 ± 0.01 mg m‐3. Additional studies should determine whether these values are applicable to the global ocean. Plain Language Summary The Biogeochemical‐Argo program is a network of ocean robots whose sensors monitor, oxygen, nitrate and chlorophyll a concentration, information which is needed to detect decadal changes in biological carbon production, ocean acidification, ocean carbon uptake, and hypoxia in the world ocean. One of the goals of the Biogeochemical‐Argo program is to incorporate these observations into ocean models to understand and forecast the changing state of the carbon cycle. The successful integration of the float data into numerical models, however, requires the specification of the observational errors. This study provides, for the first time, the biases and errors of the three cores variables of the BGC‐Argo floats network: oxygen, nitrate and chlorophyll a concentrations. PY 2019 PD APR SO Geophysical Research Letters SN 0094-8276 PU American Geophysical Union VL 46 IS 8 UT 000467949200029 BP 4330 EP 4337 DI 10.1029/2018GL080541 ID 59745 ER EF