This annual data was accessed from the PRISM project website (https://prism.oregonstate.edu/normals_other/public/alaska/grids/) and has a spatial resolution of 30 arcsec (800 m). The three climatic variables included in the dataset are total precipitation (inches), maximum temperature (degrees Fahrenheit), and minimum temperature (degrees Fahrenheit). PRISM Climate Group at Oregon State University used climate observations from monitoring stations and interpolated to a gridded format using the PRISM model (Parameter-elevation Regressions on Independent Slopes Model). Interpolation was trained using a DEM (digital elevation model) to improve performance in mountainous regions.
The PRISM temperature data were originally reported in °C but were converted to °F. The PRISM precipitation data were originally reported in millimeters but were converted to inches.
This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).
From Original PRISM Metadata (https://prism.oregonstate.edu/normals_other/public/alaska/metadata/):
Abstract:
Monthly 30-year "normal" dataset covering Alaska, averaged over the climatological period 1981–2010. Contains spatially gridded average annual precipitation and maximum temperature at 800m grid cell resolution. Distribution of the point measurements to the spatial grid was accomplished using the PRISM model, developed and applied by Dr. Christopher Daly of the PRISM Climate Group at Oregon State University. This dataset was heavily peer reviewed, and is available free-of-charge on the PRISM website.
Purpose:
Display and/or analysis requiring spatially distributed annual precipitation and temperature for the climatological period 1981–2010.
Supplementary Information:
There are many methods of interpolating climate data from monitoring stations to grid points. Some provide estimates of acceptable accuracy in flat terrain, but few have been able to adequately explain the extreme, complex variations in climate that occur in mountainous regions. Significant progress in this area has been achieved through the development of PRISM (Parameter-elevation Regressions on Independent Slopes Model). PRISM is an analytical model that uses point data and an underlying grid such as a digital elevation model (DEM) to generate gridded estimates of monthly or annual precipitation and temperature (as well as other climatic parameters). PRISM is well suited to regions with mountainous terrain, because it incorporates a conceptual framework that addresses the spatial scale and pattern of orographic processes. Grids were modeled on a monthly basis. Annual grids were produced by averaging (temperatures) or summing (precipitation) the monthly grids. Climatological data were collected for several research and government networks through a data delivery from the Arctic Landscape Conservation Cooperative's Imiq Hydroclimate Database including: the University of Alaska Fairbanks' Water and Environmental Research Center (WERC) and International Arctic Research Center (IARC); Arctic Observation Network (AON); Circumarctic Lakes Observation Network (CALON); Arctic Long Term Ecological Research (LTER); Bureau of Ocean Energy Management (BOEM); RWIS (Roadway Weather Information System); Department of Interior’s Bureau of Land Management (BLM) and Geological Survey (USGS). Climate data were also collected and processed for the National Weather Service's (NWS) Cooperative Observer Program (COOP), Weather Bureau Army/Navy (WBAN), and surface hourly stations from the National Centers for Environmental Information (NCEI); Soil Climate Analysis Network (SCAN), Snow Telemetry (SNOTEL), and Snow Course stations from the Department of Agriculture's Natural Resources Conservation Service (NRCS); Remote Automatic Weather Stations (RAWS) from the Western Regional Climate Center (WRCC) and MesoWest; Community Collaborative Rain Hail and Snow network (CoCoRaHS); National Data Buoy Center (NDBC); and the Hydrometeorological Design Studies Center (HDSC). Additional surface hourly data and the NWS Daily Hydrometeorological Product were collected via the Unidata Internet Data Distribution project (IDD). Data from the Fairbanks and Juneau Weather Forecast Offices, Alaska Department of Transportation (AKDOT), and the Hydrometeorological Automated Data System (HADS) network were also obtained from MesoWest. Data for the Central Alaska Inventory and Monitoring Network (CAKN), Juneau Icefield Research Program (JIRP), McCall Glacier, and Chugach National Forest Avalanche Information Center (CNFAIC) were made available through, or with the assistance of, the National Park Service (NPS). Data for the Alaska-Canada border region were obtained from Environment Canada, the Pacific Climate Impacts Consortium (PCIC) and NCEI.
