ECCC `CaSR` v3.2

In this file, the details of the dataset is explained.

Note

The CaSR website has been updated to include CaSR v3.2 links (v3.1 remains available on request), provide documentation describing the different CaSR versions, and introduce general usability improvements. CaSR v3.2 corrects a major issue in the precipitation analysis affecting 2005–2010 (variables: A_PR0_SFC, A_PR24_SFC, A_CFIA_SFC), mainly over Quebec, with limited effects elsewhere. This release also includes minor data improvements (see this presentation for more information): Improved of the a priori monthly precipitation quality control for 2024 (variables: A_PR0_SFC, A_PR24_SFC, A_CFIA_SFC), Masking snow depth (P_SD_LAND) and snow water equivalent (P_SWE_LAND) over non-land grid cells, and Technical update in NetCDF files with no impact on variable values.

Location of Dataset Files

The CaSR v3.2 dataset is located under the following directories accessible from multiple clusters listed below:

# DRAC Nibi (formerly Graham) cluster
/project/def-kshook/Climate_Forcing_Data/meteorological-data/casrv3.2 # def-kshook allocation

# DRAC Fir cluster
/project/rrg-alpie/data/meteorological-data/casrv3.2 # rrg-alpie allocation

# UCalgary ARC cluster
/work/comphyd_lab/data/meteorological-data/casrv3.2 # comphyd_lab allocation

and the structure of the dataset hourly files is as following:

/project/def-kshook/Climate_Forcing_Data/meteorological-data/casrv3.2
├── 1979123112.nc
├── 1980010112.nc
├── 1980010212.nc
├── 1980010312.nc
├── .
├── .
├── .
├── %Y010112.nc
├── .
├── .
├── %Y%m%d12.nc
├── .
├── .
├── %Y123112.nc
├── 2024010112.nc
├── .
├── .
├── .
└── 2024123012.nc

Coordinate Variables and Time-stamps

Coordinate Variables

The coordinate variables of the CaSRv3.2 simulations are lon and lat representing the longitude and latitude data, respectively.

Variable Time-stamps

Time-stamps The time-stamps are included in the original files.

Dataset Variables

The NetCDF files of the dataset contain 38 variables. You may see a list of variables by using the ncdump -h command on one of the files:

foo@bar:~$ ncdump -h /path/to/dataset/files/casrv3.2/2018010112.nc

Spatial Extent

The spatial extent of the CaSR v3.2 is on latitudes from +7.75 to +84.75 and longitudes from -179.9925 to 179.9728 covering North America. The resolution is 0.09 degrees (~10km).

Temporal Extent

The time-steps are hourly covering from January 1980 to December 2024.

Short Description on `CaSR` v3.2 Variables

In most hydrological modelling applications, usually 7 variables are needed detailed as following: 1) specific humidity, 2) surface pressure, 3) air temperature, 4) wind speed, 5) precipitation (surface level), 6) downward short wave radiation (surface level), and 7) downward long wave radiation (surface level). These variables are available through CaSR v3.2 dataset and their details are described in the table below:

Variable Mapping
Variable Name	CaSRv3.2 Variable	Unit	Comments
surface pressure	CaSR_v3.2_P_P0_SFC	`mb`
air temperature @20m	CaSR_v3.2_P_TT_09975	`°C`
air temperature @1.5m	CaSR_v3.2_P_TT_1.5m	`°C`
wind speed U-component @20m	CaSR_v3.2_P_UUC_09975	`kts`	Corrected U-component along West-East direction at ~20m
wind speed U-component @10m	CaSR_v3.2_P_UUC_10m	`kts`	Corrected U-component along West-East direction at ~10m
wind speed V-component @20m	CaSR_v3.2_P_VVC_09975	`kts`	Corrected V-component along South-North direction at ~20m
wind speed V-component @10m	CaSR_v3.2_P_VVC_10m	`kts`	Corrected V-component along South-North direction at ~10m
wind modulus @20m	CaSR_v3.2_P_UVC_09975	`kts`	Forecast: Wind Modulus (derived using UU and VV) at 20m
wind modulus @10m	CaSR_v3.2_P_UVC_10m	`kts`	Forecast: Wind Modulus (derived using UU and VV) at 10m
precipitation	CaSR_v3.2_A_PR0_SFC	`m/hr`	Analysis: Quantity of precipitation (CaPA 24h disaggregated hourly) at surface
short wave radiation	CaSR_v3.2_P_FB_SFC	`W m-2`	Downward solar flux at the surface
long wave radiation	CaSR_v3.2_P_FI_SFC	`W m-2`	Downward infrared flux at the surface
specific humidity @20m	CaSR_v3.2_P_HU_09975	1	Specific humidity at ~20m (0.997502 hy)
specific humidity @1.5m	CaSR_v3.2_P_HU_1.5m	1	Specific humidity at ~1.50m

Other useful variables in hydrological modelling evaluations are:

Snow and Precipitation Variables
Variable Name	CaSRv3.2 Variable	Unit	Comments
Water equivalent of snow cover	CaSR_v3.2_P_SWE_LAND	`kg m-2`	Water equivalent of snow cover at land surface subgrid tile
Snow depth	CaSR_v3.2_P_SD_LAND	`cm`	Snow depth at land surface subgrid tile
Freezing precipitation	CaSR_v3.2_P_FR0_SFC	`m`	Quantity of freezing precipitation (liquid water equivalent) at surface
Geopotential height	CaSR_v3.2_P_GZ_09975	`dam`	Geopotential height at ~20m (0.997502 hy)
Geopotential height	CaSR_v3.2_P_GZ_SFC	`dam`	Geopotential height at the surface
Liquid precipitation	CaSR_v3.2_P_RN0_SFC	`m`	Forecast: Quantity of liquid precipitation at surface
Meteorological wind direction	CaSR_v3.2_P_WDC_09975	`degree`	Forecast: Meteorological wind direction (derived using UU and VV) at ~20m (0.997502 hy)
Meteorological wind direction	CaSR_v3.2_P_WDC_10m	`degree`	Forecast: Meteorological wind direction (derived using UU and VV) at ~10m

Last updated: February 2, 2025

ECCC CaSR v3.2