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TOC > MSC data > GDPS > GDPS on MSC Datamart

Global ice analysis data in NetCDF format

Environment and Climate Change Canada provides global sea-ice analysis fields produced by its operational Global Deterministic Prediction System (GDPS) and interpolated to a rotated latitude-longitude grid with 0.09 x 0.09 degree resolution. The data files are in NetCDF format (NetCDF-4 classic model) and comply with the Climate and Forecast Conventions.

The Global Sea-Ice Analysis System is an analysis system based on 3D-Var assimilation covering all waters (ocean and lakes) at a 10km horizontal resolution on a YIN-YANG grid and using a 6 hours persistence forecast for the background state. This analysis assimilates 4 times a day satellite remote sensing data and Canadian Ice Service ice charts.

Data location

MSC Datamart data can be automatically retrieved with the Advanced Message Queuing Protocol (AMQP) as soon as they become available. An overview and examples to access and use the Meteorological Service of Canada's open data is also available.

The data is available via the HTTPS protocol. It is possible to access it with a standard browser. In this case, we obtain a list of links giving access to a NetCDF file.

The data can be accessed at the following address :

https://dd.weather.gc.ca/model_gem_global/{RES}/{HH}

where :

  • RES : Horizontal resolution [10km]
  • HH : UTC time of the beginning of the model run [00, 06, 12, 18]

A one week history is kept in this directory.

Technical specification of the grid

Values given to the various parameters of the latitude-longitude grid according to the resolution.

Parameter Value
ni 4000
nj 2000
resolution 0.09° x 0.09°

File name nomenclature

NOTE: ALL HOURS ARE IN UTC.

The files have the following nomenclature:

{YYYYMMDD}T{HH}Z_MSC_GDPS-Analysis_{VAR}_{LVLTYPE-LVL}_{Grille}{resolution}_PT{hhh}H.nc

where :

  • YYYYMMDD : Year, month, and day of the beginning of the forecast
  • T : Time delimiter according to ISO8601 norms
  • HH : UTC run time [00, 12]
  • Z : Time zone (UTC hour)
  • MSC : Constant string indicating the Meteorological Service of Canada, source of data
  • GDPS-Analysis : Constant string indicating that the data is from the Global Deterministic Prediction System ice analysis
  • VAR : Variables included in the file [IICECONC]. See variables section below
  • LVLTYPE-LVL : Vertical level type and level value [SFC]
  • Grille : Horizontal grid [RLatLon]
  • resolution : 0.09. Indicating resolution in degrees [0.09°(about 10km)] for latitude and longitude directions
  • PT{hhh}H : Forecast hours based on ISO8601 norms. P, T and H are constant character designating Period, Time and Hour. "hhh" is the forecast hour [000 for analysis]
  • nc : Constant string indicating that NetCDF format is used

Example of filename : 20210111T00Z_MSC_GDPS-Analysis_IICECONC_SFC_RLatLon0.09x0.09_PT000H.nc

List of variables

The table below provides a short description of the parameter, the level available and measurement unit, available in NetDCF format.

Support

If you have any questions about this data, please contact us.

Announcements from the dd_info mailing list

Announcements related to this dataset are available in the dd_info list.