Deep Chlorophyll Maximum global database from BioGeoChemical-Argo floats
|Temporal extent||2010-05-30 -2020-03-08|
|Author(s)||Cornec Marin1, Claustre Hervé1, Mignot Alexandre2, Guidi Lionel1, Lacour Léo3, Poteau Antoine1, D'Ortenzio Fabrizio1, Gentili Bernard1, Schmechtig Catherine1|
|Affiliation(s)||1 : Sorbonne Université, CNRS, Laboratoire d'Océanographie de Villefranche, LOV, F-06230 Villefranche-sur-Mer, France
2 : Mercator Océan International, F-31520 Ramonville-Saint-Agne, France
3 : Takuvik Joint International Laboratory, Laval University (Canada) - CNRS (France), Département de biologie et Québec-Océan, Université Laval, Québec G1V 0A6, Canada
|Keyword(s)||Deep Chlorophyll Maximum, BioGeoChemical-Argo floats, Global Ocean, Photoacclimation, Chlorophyll a, Backscattering Coefficient, Nitrates, Daily PAR, Subsurface Chlorophyll Maximum, Phytoplankton|
The dataset dcm_dtb.txt contains bio-optical measurements and environmental parameters associated with Deep Chlorophyll Maxima (DCM) acquired by BGC-Argo profiling floats.
For each BGC-Argo profile the data files includes the World Meteorological Organization (WMO) and profile numbers, the Data Assembly Center (DAC), the geographical position (LON and LAT), the date of the profile in Julian Day (JULD) and in YYYY-MM-DD format; the region of the profile (REGION, acronyms detailed in the region.txt file), the DCM zonal attribution (ZONE, acronyms detailed in the zone.txt file), the vertical resolution of measurements of the concentration of the chlorophyll a [Chla] and of the backscattering coefficient (bbp) within the 250 first meters, the Mixed Layer Depth (MLD, m), the qualification of the vertical profile (DCM_TYPE) as Deep Biomass Maximum (3), Deep photoAcclimation Maximum (2), or presenting no DCM (1); the depth of the DCM (DCM_DEPTH); the chlorophyll a concentration (CHLA_DCM, mg chla m-3 ) the backscattering coefficient (BBP_DCM, m-1), and the Brunt-Vaisala frequency (N2_DCM) at the DCM depth; the nitracline depth (NCLINE_DEPTH, m) and steepness (NCLINE_STEEP, µmol NO3 m-3 m-1), the mean nitrate concentration within the Mixed Layer (NO3_MEAN_MLD, µmol NO3 m-3), the mean daily Photosynthetically Available Radiation in the Mixed Layer (MEAN_IPAR_MLD, E m -1 d -1), the daily Photosynthetically Available Radiation at the nitracline depth (IPAR_NCLINE, E m-2 d-1); and the [Chla] measured by satellite (CHLA_SAT, mg chla m-3).
The dataset shape_NASTG_ASEW.txt contains the seasonal median, the first and third quartiles of the [Chla] and of the bbp profiles for the North Atlantic Subtropical Gyre and Atlantic SubEquatorial Waters regions.
The dataset climato_NASTG_ASEW.txt contains the monthly mean and standard deviations of the DCM depth (DCM_depth), the isolume depth of daily Photosynthetically Available Radiation of 20 E m-2 d-1 (iPAR_20), the nitracline depth, and the Mixed Layer Depth (MLD) for the profiles within the North Atlantic Subtropical Gyre and Atlantic SubEquatorial Waters regions.
The qualification and processing of the BGC-Argo profiles, as well as the DCM detection (DCM_TYPE) and the estimation of the environmental parameters, were applied as described from Cornec, M., Claustre, H., Mignot, A., Guidi, L., Lacour, L., Poteau, A., D’Ortenzio, F.,Gentili, B., Schmechtig, C., (to be updated.) Deep Chlorophyll Maxima in the global ocean: occurrences, drivers and characteristics. Global Biogeochemical Cycles, to be updated
The [Chla] satellite variable was obtained by the match of each BGC-Argo profile with a L3S [Chla] product from the Ocean Colour-Climate Change Initiative v4.0 database merging observations from MERIS, MODIS, VIIRS and SeaWiFs, at a monthly and 4x4-km-pixel resolution, up to December 31, 2019 (ftp://oc-cci-data:ELaiWai8ae@oceancolour.org/occci-v4.2/).
|Acknowledgements||This study is a contribution to the following projects: remOcean (European Research Council, Grant agreement 246777); REFINE (European Research Council, Grant agreement 834177); SOCLIM (BNP Foundation); AtlantOS (European Union's Horizon 2020 research and innovation program, Grant 2014‐633211); NAOS (Agence Nationale de la Recherche, grant agreement J11R107-F); BGC-Argo-France (CNES-TOSCA). All BGC-Argo data are available at ftp://ftp.ifremer.fr/ifremer/argo/dac/. These data were collected and made freely available by the International Argo Program and the national programs that contribute to it. (https://argo.ucsd.edu, https://www.ocean-ops.org). The Argo Program is part of the Global Ocean Observing System. Haili Wang is acknowledged for giving access to data from three floats in the South China Sea. The authors wish to thank the Argo Data Management team (ADMT) and the BGC-Argo Data Management team (BGC ADMT). Authors declare no conflict of interest.|
The float sensors were the ECO Triplet (Three Channel Sensor; WET Labs, Inc., USA) measuring the chlorophyll-a fluorescence and the scattering of light at 700 nm and an angle of 124°).