Data Access Form

Dataset Title:	Black Sea, DIVAnd 4D 6-year seasonal analysis of Water body chlorophyll-a 1990/ 2023 v2025 [observations]
Institution:	National Institute for Marine Research and Development "Grigore Antipa" (Dataset ID: oceanbrowser_opendap_719c_d076_9930)
Information:	Summary \| License \| Metadata \| Background \| Make a graph

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Dimensions	Start	Stride	Stop	Size	Spacing
observations (count)				11106	1.0 (even)

Grid Variables (which always also download all of the dimension variables)

obsdepth (depth below sea level, meters)

obslat (latitude, degrees_north)

obslon (longitude, degrees_east)

obstime (Time, seconds since 1970-01-01T00:00:00Z)

File type: (more information)

(Documentation / Bypass this form)

(Please be patient. It may take a while to get the data.)

The Dataset Attribute Structure (.das) for this Dataset

Attributes {
  observations {
    Int32 actual_range 0, 11105;
    String long_name "Observations";
    String units "count";
  }
  obsdepth {
    Float64 colorBarMaximum 8000.0;
    Float64 colorBarMinimum -8000.0;
    String colorBarPalette "TopographyDepth";
    String long_name "depth below sea level";
    String positive "down";
    String standard_name "depth";
    String units "meters";
  }
  obslat {
    Float64 colorBarMaximum 90.0;
    Float64 colorBarMinimum -90.0;
    String long_name "latitude";
    String standard_name "latitude";
    String units "degrees_north";
  }
  obslon {
    Float64 colorBarMaximum 180.0;
    Float64 colorBarMinimum -180.0;
    String long_name "longitude";
    String standard_name "longitude";
    String units "degrees_east";
  }
  obstime {
    String ioos_category "Time";
    String long_name "Time";
    String standard_name "time";
    String time_origin "01-JAN-1970 00:00:00";
    String units "seconds since 1970-01-01T00:00:00Z";
  }
  NC_GLOBAL {
    String abstract 
"Moving 6-year analysis of Water body chlorophyll-a in Black Sea for each season: winter (December-February), spring (March-May), summer (June-August), autumn (September-November). Every year of the time dimension corresponds to the 6-year centered average of the season. 6-years periods span from 1990-1995 until 2018-2023.
Data Sources: observational data from SeaDataNet/EMODNet Chemistry Data Network.
Units: mg/m^3.
DIVA analysis: The computation was done with the DIVAnd (Data-Interpolating Variational Analysis in n dimensions), version 2.7.13, using GEBCO 30sec topography for the spatial connectivity of water masses.
The horizontal resolution of the produced DIVAnd maps grids is 0.05 degrees.
The vertical resolution is 7 depth levels: 0, 5, 10, 20, 30, 40, 50m.
The horizontal correlation length: 80km.
The vertical correlation length (in meters):  twice the vertical resolution (10, 10, 20, 20, 20, 20, 20).
The error variance (epsilon2): 1 
An anamorphosis transformation was applied to the data: threshold value=200.
Background field: not used.
Quality control of the observations was applied using the interpolated field: QCMETHOD=3 and visual inspection (Observations with residuals outside the minimum and maximum values of the 99% quantile were discarded from the analysis after thoroughly visual inspection).";
    String acknowledgement "Aggregated data products are generated by EMODnet Chemistry under the support of DG MARE Call for Tenders EASME/2020/OP/0006 (EASME/EMFF/2020/3.1.11/Lot 5/SI2.846161)";
    String area_keywords "Black Sea";
    String area_keywords_urn "SDN:C19::3_3";
    String Author_e_mail "Gheorghe Sarbu <ghesarbu@gmail.com>, Luminita Buga <lbuga@web.de>";
    String bathymetry_source "The GEBCO Digital Atlas published by the British Oceanographic Data Centre on behalf of IOC and IHO, 2003. Resolution used for the analysis: 30 arc-second";
    String cdm_data_type "Grid";
    String comment "Every year of the time dimension corresponds to a 6-year centred average for the seasons: winter (Dec-Feb), spring (Mar-May), summer (Jun-Aug), autumn (Sep-Nov). Horizontal resolution 0.05Â°";
    String Conventions "CF-1.60, COARDS, ACDD-1.3";
    String creator_name "National Institute for Marine Research and Development \"Grigore Antipa\"";
    String creator_url "http://opendap.oceanbrowser.net/thredds/dodsC/data/emodnet-projects/v2025/By_sea_regions-water_body/Black_Sea/Water_body_chlorophyll-a.4Danl.nc.html";
    String date "2025-10-03T11:09:30";
    String DIVA_code_doi "10.5281/zenodo.7016823";
    String DIVA_references "Barth, A.; Beckers, J.-M.; Troupin, C.; Alvera-Azcarate, A & Vandenbulcke, L. divand-1.0: n-dimensional variational data analysis for ocean observations. Geoscientific Model Development, 2014, 7, 225-241. DOI: 10.5194/gmd-7-225-2014";
    String DIVAnd_source "https://github.com/gher-uliege/DIVAnd.jl";
    String DIVAnd_version "2.7.13";
    String doi "10.13120/8e74967a-5655-44fc-90b7-7eca192b7851";
    String file_name "By_sea_regions/Black_Sea/Water_body_chlorophyll-a.4Danl.nc";
    String history 
"Thu Oct  9 10:43:39 2025: ncks -7 -O -L 5 --baa=4 --ppc default=3 /home/ctroupin/data/EMODnet-Chemistry/Eutrophication2024/Results/By_sea_regions-water_body/Black_Sea//By_sea_regions_Black_Sea_Water_body_chlorophyll-a.4Danl.nc /home/ctroupin/data/EMODnet-Chemistry/Eutrophication2024/Results/By_sea_regions-water_body/Black_Sea//By_sea_regions_Black_Sea_Water_body_chlorophyll-a.4Danl.nc
2026-03-14T01:17:54Z http://opendap.oceanbrowser.net/thredds/dodsC/data/emodnet-projects/v2025/By_sea_regions-water_body/Black_Sea/Water_body_chlorophyll-a.4Danl.nc
2026-03-14T01:17:54Z https://erddap.emodnet.eu/erddap/griddap/oceanbrowser_opendap_719c_d076_9930.das";
    String id "DatasetScan/emodnet-projects/v2025/By_sea_regions-water_body/Black_Sea/Water_body_chlorophyll-a.4Danl.nc";
    String infoUrl "http://opendap.oceanbrowser.net/thredds/dodsC/data/emodnet-projects/v2025/By_sea_regions-water_body/Black_Sea/Water_body_chlorophyll-a.4Danl.nc.html";
    String institution "National Institute for Marine Research and Development \"Grigore Antipa\"";
    String institution_urn "SDN:EDMO::697";
    String keywords "6-year, analysis, antipa, below, black, body, chla, chlorophyll, chlorophyll-a, control, data, depth, development, divand, grigore, institute, latitude, level, longitude, marine, national, obsdepth, observations, obslat, obslon, obstime, quality, research, sea, seasonal, seawater, time, v2025, water, year";
    String license 
"The data may be used and redistributed for free but is not intended
for legal use, since it may contain inaccuracies. Neither the data
Contributor, ERD, NOAA, nor the United States Government, nor any
of their employees or contractors, makes any warranty, express or
implied, including warranties of merchantability and fitness for a
particular purpose, or assumes any legal liability for the accuracy,
completeness, or usefulness, of this information.";
    String NCO "netCDF Operators version 5.2.1 (Homepage = http://nco.sf.net, Code = https://github.com/nco/nco, Citation = 10.1016/j.envsoft.2008.03.004)";
    String parameter_keyword "Water body chlorophyll-a";
    String parameter_keyword_urn "SDN:P35::EPC00105";
    String product_code "Black_Sea-Water_body_chlorophyll-a-v2025-ANA";
    String product_id "8e74967a-5655-44fc-90b7-7eca192b7851";
    String product_version "1.0";
    String project "EMODnet-Chemistry";
    String search_keywords "Chlorophyll pigment concentrations in water bodies";
    String search_keywords_urn "SDN:P02::CPWC";
    String source "Observational data from SeaDataNet/EMODNet Chemistry Data Network";
    String sourceUrl "http://opendap.oceanbrowser.net/thredds/dodsC/data/emodnet-projects/v2025/By_sea_regions-water_body/Black_Sea/Water_body_chlorophyll-a.4Danl.nc";
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary 
"Black Sea - DIVAnd 4D 6-year seasonal analysis of Water body chlorophyll-a 1990/2023 v2025. Moving 6-year analysis of Water body chlorophyll-a in Black Sea for each season: winter (December-February), spring (March-May), summer (June-August), autumn (September-November). Every year of the time dimension corresponds to the 6-year centered average of the season. 6-years periods span from 1990-1995 until 2018-2023.
Data Sources: observational data from SeaDataNet/EMODNet Chemistry Data Network.
Units: mg/m^3.
DIVA analysis: The computation was done with the DIVAnd (Data-Interpolating Variational Analysis in n dimensions), version 2.7.13, using GEBCO 30sec topography for the spatial connectivity of water masses.
The horizontal resolution of the produced DIVAnd maps grids is 0.05 degrees.
The vertical resolution is 7 depth levels: 0, 5, 10, 20, 30, 40, 50m.
The horizontal correlation length: 80km.
The vertical correlation length (in meters):  twice the vertical resolution (10, 10, 20, 20, 20, 20, 20).
The error variance (epsilon2): 1 
An anamorphosis transformation was applied to the data: threshold value=200.
Background field: not used.
Quality control of the observations was applied using the interpolated field: QCMETHOD=3 and visual inspection (Observations with residuals outside the minimum and maximum values of the 99% quantile were discarded from the analysis after thoroughly visual inspection).";
    String title "Black Sea, DIVAnd 4D 6-year seasonal analysis of Water body chlorophyll-a 1990/2023 v2025 [observations]";
    String WEB_visualisation "https://emodnet.ec.europa.eu/geoviewer/";
  }
}

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and its projection constraints (external link)

The URL specifies what you want: the dataset, a description of the graph or the subset of the data, and the file type for the response.

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For example,
https://coastwatch.pfeg.noaa.gov/erddap/griddap/jplMURSST41.htmlTable?analysed_sst[(2002-06-01T09:00:00Z)][(-89.99):1000:(89.99)][(-179.99):1000:(180.0)]
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