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.
The Seaglider is sg562 (WMO ID 6801612). SBE-CT sail (SN 191) was last calibrated on 3 November 2017.
The optode AA4330 (SN 797) was last calibrated on 29 January 2018. The glider was deployed on 7 October 2020,
went into recovery mode on 8 February 2021, and was recovered on 10 February 2021. The last good profile
was on 7 February.
The sampling rate was variable. In the first 129 dives, sampling rate was 10 s in the entire 1000 m. Later on,
10 s in the upper 600 m and 15 s below 600 m in dives 130 to 173, and 13 s in the upper 600 m and 20 s below 600 m
for the rest of the mission (dives 174 to 625).
The data are processed using the University of East Anglia Seaglider toolbox (http://www.byqueste.com/toolbox.html)
downloaded on 25 March 2021 (most recent toolbox change prior to download was 15 September 2020). The processing
is based on the methods described by Garau et al. (2011) for the thermal lag correction of the conductivity cell,
and Frajka-Williams et al. (2011) for the flight model regression. TEOS-10 is used (IOC, SCOR, and IAPSO 2010).
Hard limits on salinity and temperature were applied to exclude obvious outliers before the flight model regression.
Variable pitch and roll dives are selected for the flight model regression and 30 m range from the surface and apogee
are excluded. Correction coefficients for the thermal lag of the conductivity cell are obtained minimizing the area
between the up and down temperature-salinity curves as described in Garau et al. (2011). Improved salinity values are
then obtained accounting for the thermal lag. Unfortunately, salinity profiles obtained from this mission are particularly
problematic, despite the best estimates for flow past sensor and thermal lag corrections. Substantial manual flagging was
applied to salinity and density profiles to remove spikes and unstable overturns appearing in density profiles. After manual
flagging, each profile is despiked by flagging values exceeding twice the rms value of (x – xs), where x is the profile data
and xs is a 5-point median filter. In addition, data in the upper 5 m in dives and 1 m in climbs, and in the bottommost 5 m
in dives and climbs are flagged. All flagged data, either detected automatically or manually, are replaced by NaNs.
The density profile is sorted (retaining NaNs), and salinity is obtained from the gravitationally stable density profile.
The user is warned about this nonstandard approach.
Normally, processed Absolute Salinity and Conservative Temperature are accurate to 0.01 g kg-1 and 0.001C, respectively,
and DAC is accurate to 0.01 m s-1 (p. 9 “Seaglider Quality Control Manual,” 2012). However, we expect unquantified uncertainties
in salinity at finescale (1-5 m) because it is calculated from the sorted density profile. Furthermore, DAC values for the
dives under sea ice (dives 422-425) and dives missing GPS fix (230-231, 235-236) are not accurate and obtained by linear interpolation of the last known
predive and postdive positions.