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.
This data set is a collection of publicly available hydrographic and geochemical observations in and around the Nordic Seas, within the domain 50-90˚N and 45˚W-45˚E, over the period 1950-2019. It consists of vertical profiles of temperature, salinity, oxygen, nitrate, and phosphate mainly collected by shipboard CTDs and water bottles, as well as Argo float profiles. All observations were combined into a single data set and quality controlled as described in Brakstad et al., (2023) (https://doi.org/10.1016/j.pocean.2023.102981). The quality control involves removing duplicates between the source archives, erroneous profiles, density inversions, and outliers. The final quality-controlled data set consists of 608 804 hydrographic profiles and 330 026 geochemical profiles, that can be easily accessed for any water mass analyses in the Nordic Seas.
Observations of temperature, salinity, oxygen, nitrate, and phosphate during 2000-2019 are used to create a late-winter (February to April) climatology of the Nordic Seas. All observations were modified to represent late-winter conditions, when the mixed layer is deepest and densest, by homogenizing each hydrographic and geochemical profile from the local late-winter mixed-layer depth to the surface (Brakstad et al., 2023: https://doi.org/10.1016/j.pocean.2023.102981). The observations were then interpolated onto a three-dimensional grid with a regular horizontal resolution of 1/3˚ longitude and 1/8˚ latitude, and 46 vertical levels with intervals ranging from 10m near the surface to 250m at depth. The corresponding observational uncertainties were estimated based on the number of observations included in each grid cell and their variance. In general, the uncertainty decreases with depth due to the lower variance at depth and with increased number of observations. The final late-winter hydrographic and geochemical climatology and the associated uncertainties cover the domain 58.5-84.0˚N and 45.0˚W-45.0˚E.