PCIC meteorology for northwestern North America (PNWNAmet)

Overview

The PNWNAmet dataset covers a domain of northwest North America (NWNA; 40°N to 72°N and -169°W to -101°W) at a spatial resolution of 1/16° (~6 km). PNWNAmet uses the trivariate thin plate spline interpolation method with the algorithm implemented by Nychka et al. (2017). Precipitation was interpolated using latitude, longitude and a 1971-2000 climatology from ClimateWNA (v5.10) as predictors. ClimateWNA uses bilinear interpolation and an elevation adjustment to create a scale-free, smooth at the boundaries, mosaic of available climatologies.

Provider's contact information

This dataset was created circa 2014 by Werner et al. (2019) at the Pacific Climate Impacts Consortium (PCIC).

Licensing

Freely available for download at https://data.pacificclimate.org/portal/gridded_observations/map/

Variable name and units:

Total precipitation (mm)

Spatial coverage and resolution:

The dataset has a 1/16° (~6 km) spatial resolutions and covers the northwestern part of Canada and Alaska. The Eastern limit is slightly to the east of Saskatchewan and Yukon Territory.

NWNA: 40°N to 72°N and -169°W to -101°W

Temporal coverage and resolution:

Temporally consistent gridded daily meteorological data for northwest North America covering 1945 through 2012.

Information about observations (number, homogeneity)

The PNWNA Precipitation dataset over Canada is based on station records from the second generation of Environment and Climate Change Canada’s (ECCC) Adjusted and Homogenized Canadian Climate Data (AHCCD). Corresponding daily data from the conterminous United States was from the United States Historical Climatology Network-Daily (USHCN-Daily). Daily data (not homogenized) for Alaska were from the Global Historical Climatology Network-Daily (GHCN-Daily). Selected stations had to have at least 40 years of complete record (<10% missing days within a year) over the 1945–2012 period. To supplement areas with sparse observations along the periphery of the domain, specifically around the western and northern coasts of Alaska, daily outputs from the 20th Century Reanalysis V2 (20CR2) were used as virtual stations. For precipitation, the median number of reporting stations was 442 (minimum of 262 and maximum of 476).

Methodology

The PNWNAmet dataset is based on daily precipitation (and other variables) of the homogeneized Canadian AHCCD station data and USHCN-Daily station data that is subject to a number of additional quality assurance checks. The interpolated grid was generated using the trivariate thin plate spline interpolation method, as implemented by Nychka et al. (2017) which is similar to the algorithm used for the ANUSPLIN dataset. However, PNWNAmet uses ClimateWNA v5.10 monthly climate normals rather than elevation as the third predictor variable, where 5 different climatologies were merged to a single spatially homogeneous, 1971–2000 monthly climatology (Werner et al. 2019).

Information about the technical and scientific quality

The PNWNAmet dataset was designed as a dataset well suited for driving hydrological models and training statistical downscaling schemes. It performs comparably well to two gridded meteorological datasets (NRCANmet = ANUSPLIN and PBCmet), for standardize performance measures against an independent climate network for climatology, extremes and variability. However, it potentially has a greater number of wet days than other gridded meteorological datasets, which may be due to its lower stations density. It performs better than other datasets in terms of resolving the timing of periods of increasing/decreasing precipitation and minimum temperature in the observed series than the NRCANmet and PBCmet datasets, while PBCmet performs slightly better for maximum temperature. Based on a comparison between PNWNAmet and NRCANmet climatologies, PNWNAmet likely better resolves spatial patterns of precipitation. (Werner et al., 2019).

Limitations and strengths for application in North Canada

The dataset was specifically designed for hydrological applications and statistical downscaling of climate simulation data. However it only covers the western part of Canada.

References to documents describing the methodology or/and the dataset

PCIC Website: https://www.pacificclimate.org/data/daily-gridded-meteorological-datasets

Werner, A.T., M. A. Schnorbus, R. R. Shrestha, A. J. Cannon, F. W. Zwiers, G. Dayon G., and F. Anslow, 2019: A long-term, temporally consistent, gridded daily meteorological dataset for northwestern North America, Scientific Data, 6, 180299, doi:10.1038/sdata.2018.299

Link to download the data and format of data:

Data citation:

Werner, A. T. et al. fig share https://doi.org/10.6084/m9.figshare.c.3965337 (2018).

The data can also be found at the Pacific Climate Impacts Consortium’s public and persistent data portal at https://data.pacificclimate.org/portal/gridded_observations/map/

Publications including dataset evaluation or comparison with other data in northern Canada

Eum, H.-I. and A. Gupta, 2019: Hybrid climate datasets from a climate data evaluation system and their impacts on hydrologic simulations for the Athabasca River Basin in Canada, Hydrol. Earth Syst. Sci., 23, 5151–5173, https://doi.org/10.5194/hess-23-5151-2019.