Simulations are assembled from raw downloaded files into single historical+SSP 151 year (1950-2100) daily simulations for each variable (pr, tasmax, tasmin) and scenario (SSP126, SSP245, SSP585).
GCM Checks:
Time series matches raw GCM downloads, and increases monotonically by day.
Spatial coordinates match the raw GCM downloads.
Global GCMs are subset to North American domain prior to downscaling and the spatial extent of the GCMs must span 180oE to 310oE and 5oN to 88oN.
Verification of BCCAQv2 downscaled CMIP6 GCM simulations
Checks are performed on each downscaled simulation
Time series matches the driving GCM and increases monotonically by day.
Spatial dimensions and coordinates match target dataset (ANUSPLIN) spatial coordinates.
NA check – flag any missing values in cells in the downscaled simulations with valid data in the same cells in the target dataset.
Dataset maxima and minima – calculate the series total maximum and minimum values at each downscaled grid cell. Verify daily precipitation values are < 1000 mm and daily temperature values are between -100 degC and 100 degC.
Derived Variables
A set of climate indices are calculated from each downscaled GCM (see below).
Verify derived variables are calculated successfully with no missing cells.
Visual inspection of derived variable files to look for clear errors or problems.
List of derived variables
Averages/Totals
Annual, seasonal, monthly averages of daily maximum temperature
Annual, seasonal, monthly averages of daily minimum temperature
Annual, seasonal, monthly totals of daily precipitation
Annual Extremes
Annual maximum daily maximum temperature
Annual minimum daily minimum temperature
Annual maximum daily precipitation
Annual Extremes
Annual maximum daily maximum temperature
Annual minimum daily minimum temperature
Annual maximum daily precipitation
Climdex
Standard set of 27 ETCCDI Climdex indices.
Additional indices:
RX2day precipitation
R95days (no. of days with daily precipitation > 95th percentile
R99days (no. of days with daily precipitation > 99th percentile
SU30 (no. days with daily maximum temperature > 30oC)
Degree Days
Cooling Degree Days (18oC threshold)
Heating Degree Days (18oC threshold)
Growing Degree Days (5oC threshold)
Freezing Degree Days (0oC threshold)
Known Issues
Temperature Reversals
In some instances daily maximum temperature can be less than daily minimum temperature. This is due to the existence of similar temperature reversals in the ANUSPLIN target dataset, and because BCCAQv2 is a univariate method where maximum and minimum temperature downscaled separately.
Localized large daily precipitation events
Anomalously large daily precipitation values (300 - 500 mm) at isolated locations in Yukon, southern Ontario, and central Quebec can occur in the downscaled simulations due to similar events in the ANUSPLIN target dataset. These appear substantially larger than the surrounding regions.
Discontinuous daily precipitation spatial patterns
The combination of sharp boundaries between zero and non-zero precipitation in ANUSPLIN and the within re-ordering step of BCCAQv2 can cause spatial patterns of daily precipitation to appear discontinuous with sharp changes in precipitation amount over short distances.
Verification of CMIP6 GCMs
Verification of BCCAQv2 downscaled CMIP6 GCM simulations Checks are performed on each downscaled simulation
Derived Variables
List of derived variables Averages/Totals
Known Issues
Temperature Reversals In some instances daily maximum temperature can be less than daily minimum temperature. This is due to the existence of similar temperature reversals in the ANUSPLIN target dataset, and because BCCAQv2 is a univariate method where maximum and minimum temperature downscaled separately.
Localized large daily precipitation events Anomalously large daily precipitation values (300 - 500 mm) at isolated locations in Yukon, southern Ontario, and central Quebec can occur in the downscaled simulations due to similar events in the ANUSPLIN target dataset. These appear substantially larger than the surrounding regions.
Discontinuous daily precipitation spatial patterns The combination of sharp boundaries between zero and non-zero precipitation in ANUSPLIN and the within re-ordering step of BCCAQv2 can cause spatial patterns of daily precipitation to appear discontinuous with sharp changes in precipitation amount over short distances.