Copernicus Marine Service Arctic MFC: Validation of temperature and salinity profiles
Computation of anomaly correlations include use of monthly depth interval (layer) climatologies. These were derived from the World Ocean Atlas data.
Validation based on data from profiling buoys
Validation of the Copernicus Marine Arctic MFC results for ocean temperature, salinity and mixed layer depth is performed using data from profiling buoys, which are compiled by the Copernicus Marine In Situ TAC. New sets of buoy data are available daily, while each buoy provides one profile for each 10-day period. The data are available from Argo buoys, with most buoys covering a depth range of 0-2000 m. Read more about the Argo project here.
Bias is defined as averages of model values - observed values.
Profile data are available from the Copernicus Marine Sea Surface Temperature TAC as product INSITU_ARC_NRT_OBSERVATIONS_013_031, and from a web interface to the NMD data (in Norwegian).
Validation based on data from CTD profiles
The ARGO program does not provide observations from shelf regions. Therefore, the above validation is complemented by comparisons of model results and CTD profiles from scientific-level cruises. These validation statistics is updated on a quarterly basis.
Maps show temperature and salinity bias averaged over the water column from 5 m depth to 2000 m depth, or the bottom (model or actual) or maximum CTD depth in places where the bottom (model or actual) or maximum CTD depth is less than 2000 m. For the mixed-layer depth comparison, the bias is set to zero if both the model and observations indicate mixing to the bottom, irrespective of any differences in model and actual bottom depth in the position.
CTD data are downloaded from the Copernicus Marine product INSITU_ARC_NRT_OBSERVATIONS_013_031.
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Validation based on data from ITPs
The ARGO program does generally not provide observations from the Arctic Ocean. Therefore, the above validation is complemented by comparisons of model results and observations from Ice Tethered Profilers (ITPs). Read more about Ice Tethered Profilers here.
Woods Hole Oceanographic Institution (WHOI) coordinates the ITP program. Data may be downloaded as part of the Copernicus Marine product INSITU_ARC_NRT_OBSERVATIONS_013_031. The present locations of active ITPs are shown on a map from the web pages from WHOI.
Layers
Validation of temperature and salinity profiles is conducted for depth averaged values in pre-defined depth intervals (layers). The intervals are
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Regions
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The ocean circulation model used in Copernicus Marine Arctic MFC covers the Arctic Ocean, the North Atlantic Ocean and adjacent ocean regions. The northern part is depicted in the figure to the left. Validation of temperature and salinity profiles from model results are performed for two domains:
However, note that there are rarely any ARGO profile data north of the Nordic Seas, so almost all ARGO observations are either inside of the green region, or in the North Atlantic Ocean and the Labrador Sea (the part of the blue region to the south and to the west of the Nordic Seas). A sample map of the distribution of ARGO profiles (right) illustrates this limitation. ITP data are available from the Arctic Ocean only. |
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ARC-MFC PHYS
The model results are produced with the TOPAZ ocean data assimilation model system (Copernicus Marine product ARCTIC_ANALYSIS_FORECAST_PHYS_002_001_a). Presently, TOPAZ is run weekly with data assimillation one week prior to the bulletin date, followed by a one-week 100 member ensemble simulation ending on the bulletin date, and finally a 10 day deterministic forecast. TOPAZ was developed and is maintained by the Nansen Center.
ARC-MFC PHYS (TOPAZ) results are available as Copernicus Marine product ARCTIC_ANALYSIS_FORECAST_PHYS_002_001_a. An archive of historical forecasts are available from a thredds server.
