This data is derived from the daily climate estimates (historical) and projections (future) through two steps. First, indicators are computed at a yearly scale from the daily data values using the xclim library (https://xclim.readthedocs.io/en/stable/), giving values for each indicator for each year in the range of 1980-2099. Second, those yearly indicator values are summarized by minimum, mean, and maximum operations over one historical era (1980-2009) and two future eras (2040-2069, 2070-2099).

This dataset contains data from two global climate models (GCMs), NCAR-CCSM$ and MRI-CGCM3, and one historical estimated product, Daymet.

Data files are GeoTIFFs (.tif) and are named as follows:

ncar12km_indicators_<indicator name>_<summary era>_<model>_<scenario>_<summary statistic>.tif

Here are the following indicators available in this dataset:

hd: “Hot day” threshold -- the highest observed daily maximum 2 m air temperature such that there are 5 other observations equal to or greater than this value.

cd: “Cold day” threshold -- the lowest observed daily minimum 2 m air temperature such that there are 5 other observations equal to or less than this value.

rx1day: Maximum 1-day precipitation

su: "Summer Days" –- Annual number of days with maximum 2 m air temperature above 25 C

dw: "Deep Winter days" –- Annual number of days with minimum 2 m air temperature below -30 C

wsdi: Warm Spell Duration Index -- Annual count of occurrences of at least 5 consecutive days with daily mean 2 m air temperature above 90th percentile of historical values for the date

cdsi: Cold Spell Duration Index -- Same as WDSI, but for daily mean 2 m air temperature below 10th percentile

rx5day: Maximum 5-day precipitation

r10mm: Number of days with precipitation > 10 mm

cwd: Consecutive wet days –- number of the most consecutive days with precipitation > 1 mm

cdd: Consecutive dry days –- number of the most consecutive days with precipitation < 1 mm

The source downscaled climate dataset used here is the "21st Century Hydrologic Projections for Alaska and Hawaii" developed by the UCAR/NCAR Research Applications Laboratory (https://doi.org/10.5065/c3kn-2y77; associated paper can be found at https://doi.org/10.1016/j.cliser.2022.100312 ).

The code used for developing this dataset can be found on GitHub at https://github.com/ua-snap/ardac-curation/tree/4b39c69df1841701e6f5b9d6e06815b4167fc8fa/ncar12km_indicators.