Deep Chlorophyll Maximum global database from BioGeoChemical-Argo floats

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/).

Disciplines

Biological oceanography

Keywords

Deep Chlorophyll Maximum, BioGeoChemical-Argo floats, Global Ocean, Photoacclimation, Chlorophyll a, Backscattering Coefficient, Nitrates, Daily PAR, Subsurface Chlorophyll Maximum, Phytoplankton

Location

90N, -90S, 180E, -180W

Devices

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°).

Data

FileSizeFormatProcessingAccess
DCM identification and related environmental characteristics from the BGC Argo database
15 MoCSVProcessed data
Climatologies of the DCM depth, nitracline, isolume of 20 E m-2 d-1, and MLD in the NASTG and ASEW regions
5 KoCSVProcessed data
Seasonal vertical distribution of the [Chla] and bbp in the NASTG and ASEW regions
528 KoCSVProcessed data
Description of the regional acronyms used in the dcm_dtb.txt file
920 octetsCSVProcessed data
Description of the zonal acronyms used in the dcm_dtb.txt file
120 octetsCSVProcessed data
How to cite
Cornec Marin, Claustre Hervé, Mignot Alexandre, Guidi Lionel, Lacour Léo, Poteau Antoine, D'Ortenzio Fabrizio, Gentili Bernard, Schmechtig Catherine (2020). Deep Chlorophyll Maximum global database from BioGeoChemical-Argo floats. SEANOE. https://doi.org/10.17882/77207
In addition to properly cite this dataset, it would be appreciated that the following work(s) be cited too, when using this dataset in a publication :
Cornec M., Claustre H., Mignot A., Guidi L., Lacour L., Poteau A., D'Ortenzio F., Gentili B., Schmechtig C. (2021). Deep Chlorophyll Maxima in the global ocean: occurrences, drivers and characteristics. Global Biogeochemical Cycles. 35 (4). e2020GB006759 (30p.). https://doi.org/10.1029/2020GB006759, https://archimer.ifremer.fr/doc/00685/79669/

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