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TOC > MSC data > RAQDPS > Regional Air Quality Deterministic Prediction System on MSC Datamart

Regional Air Quality Deterministic Prediction System (RAQDPS) data in GRIB2 Format

This page describes the Regional Air Quality Deterministic Prediction System (RAQDPS) GRIB2 data. The system is run twice daily to produce 72-hour forecasts of some pollutants such as hourly ozone (O3), nitrogen dioxide (NO2), or particulate matter with aerodynamic diameter smaller than 2.5 μm (PM2.5) fields on a North American grid.

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 can be accessed at the following URLs:

where:

  • HH : Model run start, in UTC [00, 12]
  • hhh : Forecast hour [000, 001, 002, ..., 072]

A history of 24 days of forecast is kept in this directory.

Technical specification of the grid

RAQDPS grid image

Table lists the values of various parameters of the rotated lat-lon grid:

Parameter Value
ni 729
nj 599
resolution at 60° N 10 km
coordinate of first grid point (with respect to the used grid) 32 ° S ; 39.5 ° W

Note : The most recent versions of wgrib2 and GDAL support these rotated grids.

File nomenclature

NOTE: ALL HOURS ARE IN UTC.

The files have the following nomenclature:

{YYYYMMDD}T{HH}Z_MSC_RAQDPS_{VAR}_{LVL}_{Grille}(resolution}_PT{hhh}H.grib2

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
  • RAQDPS : Constant string indicating that data is from the Regional Air Quality Deterministic Prediction System
  • VAR : Variable type included in the file [PM2.5, PM10, NO2, NO, O3, SO2]
  • LVL : Vertical level [Sfc for the surface, EAtm for the column integral]
  • Grille : Horizontal grid rotated lat-lon [RLatLon]
  • resolution : Indicating resolution in degreee, here 0.09°x0.09° (about 10km) in latitude and longitude directions [0.09]
  • 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, 001, 002, ..., 072]
  • grib2: Constant string indicating the GRIB2 format is used

Example of forecast file name:

  • 20200521T00Z_MSC_RAQDPS_NO2_Sfc_RLatLon0.09_PT003H.grib2

List of variables

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.