The core partner data centres that are integrated in NorDataNet are listed in https://www.nordatanet.no/en/node/69. In addition to this NorDataNet harvests information on relevant datasets from a number of other data centres. The data centre responsible for the data presented is usually (but not always) listed in the discovery metadata. In essence NorDataNet is an aggregating service that combines information from a number of existing data centres.
Citation of data and service
If you use data retrieved through this portal, please acknowledge our funding source:
Research Council of Norway, project number 245967/F50, Norwegian Scientific Data Network.
Always remember to cite data when used!
Citation information for individual datasets is often provided in the metadata. However, not all datasets have this information embedded in the discovery metadata. On a general basis a citation of a dataset include the same components as any other citation:
author, title,
year of publication,
publisher (for data this is often the archive where it is housed),
edition or version,
access information (a URL or persistent identifier, e.g. DOI if provided)
All partner repositories of NorDataNet support Digital Object Identifiers (DOI), but not all datasets are minted. Whether or not minted depends often on source of the data (e.g. operational data are often yet not minted). However, all data centres support persistent identifiers according to local systems. The information required to properly cite a dataset is normally provided in the discovery metadata the datasets.
Brief user guide
The Data Access Portal has information in 3 columns. An outline of the content in these columns is provided above. When first entering the search interface, all potential datasets are listed. Datasets are indicated in the map and results tabulation elements which are located in the middle column. The order of results can be modified using the "Sort by" option in the left column. On top of this column is normally relevant guidance information to user presented as collapsible elements.
If the user want to refine the search, this can be done by constraining the bounding box search. This is done in the map - the listing of datasets is automatically updated. Date constraints can be added in the left column. For these to take effect, the user has to push the button marked search. In the left column it is also possible to specific text elements to search for in the datasets. Again pushing the button marked "Search" is necessary for these to take action. Complex search patterns can be constructed using logical operators identified in the drop down menu with and phrases embedded in quotation marks. Prefixing a phrase with '-' negates the phrase (i.e. should not occur in the results). Searches are case insensitive.
Other elements indicated in the left and right columns are facet searches, i.e. these are keywords that are found in the datasets and all datasets that contain these specific keywords in the appropriate metadata elements are listed together. Further refinement can be done using full text, date or bounding box constraints. Individuals, organisations and data centres involved in generating or curating the datasets are listed in the facets in the right column. The combination of search fields (including facets) is based on a logical "AND" combination of the fields, i.e. all conditions are fulfilled for the results provided.
Phytoplankton, pigment, bacteria and biogeochemistry data from an ecosystem cruise to Kong Håkon VII Hav, Southern Ocean, in March 2019 with the R/V Kronprins Haakon. Also included are glider data for a deployment that happened during the same cruise to Kong Håkon VII Hav, Southern Ocean, in March 2019.
Quality
Chlorophyll (Chl) a samples were collected from multiple depths, filtered (500-1000 ml, typically 1000 ml) with a gentle vacuum pressure on 0.7 um GF/F filters, and extracted in 100 % methanol in darkness, 5° C and for 24 h. Pigment concentration was measured with a calibrated Turner 10-AU Fluorometer (Turner Designs, San Jose, USA).
Flow cytometry samples (FCM) were filled in 4.5 ml cryovials, fixed with glutaraldehyde (final concentration 0.5 %), and stored in -80° C until analysis. The samples were analysed with a Attune™ NxT Acoustic Focusing Cytometer (Invitrogen™, Thermo Fisher Scientific Inc. USA) at the University of Bergen, Norway 6 months after the campaign (September 2019). Before the analysis, the bacteria samples were diluted (10x) with filtered TE buffer, stained with SYBR Green I and incubated at room temperature in darkness for 10 minutes. Bacteria concentration estimates were based on side scatter and green fluorescence. Pico- and nanophytoplankton concentration estimates (included in version 2) were based on side scatter and red fluorescence.
Samples for HPLC analysis were collected in the same way and stored in -80° C until analysis at the Alfred Wegener Institute (Bremen, Germany) with a Waters Alliance 2695 HPLC Separation Module, Waters photodiode array detector (2,996), Agilent Technologies Microsorb-MV3 C8 column (4.6 × 100 mm), and 1 molar ammonium acetate solution. For more details see the below mentioned articles. Header explanations: Chla - chlorophyll a; Chlb - chlorophyll b; Chlc1_Chlc2 - chlorophyll c1 + chlorophyll c2; Chlc3 - chlorophyll c3; Fucox - fucoxanthin; 19But - 19’butanoyloxyfucoxanthin; 19Hex - 19’hexanoyloxyfucoxanthin; Perid - peridinin; Lutein - lutein; Allox – alloxanthin; Zeax - zeaxanthin; DD - diadinoxanthin; DT – diatoxanthin; Beta_car - beta carotene.
Also included here Chl a concentrations from an underway fluorometer (WETStar, Sea-Bird Scientific; scientific seawater intake at 4 m depth) calibrated with Chl a samples (taken every 4 hours during longer transits; y=0.09x + 0.06; R2=0.85) processed with the above mentioned method.
Unpublished data to be included in future versions (v3): biogenic silica, particulate organic carbon and nitrogen (POC and PON), dissolved organic carbon (DOC) and total dissolved nitrogen (TDN).
Chlorophyll (Chl) a profiles obtained with vertical in situ fluorescence measurements on an ecosystem cruise to Kong Håkon VII Hav, Southern Ocean, in March 2019 with the R/V Kronprins Haakon.
Quality
In situ Chl a fluorescence was measured with a WETLabs ECO fluorometer, bin-averaged to 1 m bins, corrected for baseline shifts (certain stations; the difference between the mode value of the station in question and the global dataset mode was added) and calibrated (fitted linearly) with the help of the determined dark value (the mode of values below 500 m) and concurrent Chl a values from water samples. The upcast values (median of a 2 m window around the water sampling depth) were used for the calibration as water sampling happened during the upcast, whereas downcast values are included in this dataset (both as mat and netCDF file) as the water column is less disturbed during the downcast. R2 of the fit was 0.74 and 0.67 before and after a sensitivity setting change (data treated separately), respectively. Please note that the data are not corrected for non-photochemical fluorescence quenching (NPQ). CO2 (https://doi.org/10.4319/lom.2012.10.483) data.
Mat file variable explanations: chla: Chlorophyll a concentration in mg/m3 depth: sampling (measurement) depth in meter lat: latitude in degrees south lon: longitude in degrees east sampling_time: the different columns contain the year, month, day, hour and minute of the sampling time station_number: CTD station running number starting with number 52
=== In this dataset there are also included mixed layer depths (MLD; z_mld) for the stations (mat and csv files). Fluorescence measurements were done in connection with CTD (conductivity-temperature-depth) casts (SBE911+ system). MLD was defined as the depth where salinity increases by 0.01 between two pressure binned values (1 m bin size). The upper 15 m of the profiles was discarded due to spikes and possible disturbances by the ship and the profiles were filtered with a 7 pt running median filter to remove spikes.