Historical and Projected Dynamically Downscaled Climate Data for the State of Alaska and surrounding regions at 20km spatial resolution and hourly temporal resolution

This dataset contains historical and projected dynamically downscaled climate data for the State of Alaska and surrounding regions at 20km spatial resolution and hourly temporal resolution. Select variables are also summarized into daily resolutions. This data was produced using the Weather Research and Forecasting (WRF) model (Version 3.5). We downscaled both ERA-Interim historical reanalysis data (1979 - Oct 2015) and both historical and projected runs from 2 GCM’s from the Coupled Model Inter-comparison Project 5 (CMIP5): GFDL-CM3 and NCAR-CCSM4 (historical run: 1970-2005 and RCP 8.5: 2006-2100).

Note, this data is not bias-corrected. It can be considered synonymous with utilizing raw CMIP5 output but at higher spatial and temporal resolutions. If a direct application to real-world situations is needed, bias correction should be an essential first step in your analysis.

Data are provided as NetCDF files closely following Climate and Forecasting (CF) metadata conventions, but may not be fully compliant. It is output on a 20x20km grid in a WRF-derived polar stereographic projection system at an hourly time-step. Some outputs have also been further aggregated to daily timesteps.

**Variables include:**

Variable | Description
ACSNOW | Water equivalent of accum. snow depth
ALBEDO | Albedo
CANWAT | Plant canopy surface water
CLDFRA | Total cloud cover
CLDFRA_HIGH | High level cloud cover
CLDFRA_LOW | Low level cloud cover
CLDFRA_MID | Mid level cloud cover
GHT | Geopotential height
HFX | Sensible heat flux
LH | Latent heat flux
LWDNB | Downward long wave flux
LWDNBC | Clear sky downward long wave flux
LWUPB | Upward long wave flux
LWUPBC | Clear sky upward long wave flux
OMEGA | Pressure vertical velocity
PCPC | Accumulated total precipitation
PCPNC | Accumulated large-scale precipitation
PCPT | Total precipitation
POTEVP | Accumulated potential evaporation
PSFC | Surface pressure
Q2 | Specific humidity at 2m height
QBOT | Specific humidity at lowest model level
QVAPOR | Specific humidity
SEAICE | Ice concentration
SH2O | Liquid volumetric soil moisture (non-frozen)
SLP | Mean sea level pressure (ETA model)
SMOIS | Volumetric soil moisture content
SNOW | Snow water equivalent
SNOWC | Snow cover
SNOWH | Snow depth
SWDNB | Downward short wave flux
SWDNBC | Clear sky downward solar flux
SWUPB | Upward short wave flux
SWUPBC | Clear sky upward solar flux
T | Temperature
T2 | Temperature at 2m height
TBOT | Temperature at lowest model level
TSK | Surface skin temperature
TSLB | Soil temperature
U | u-component of wind
U10 | u-component of wind at 10m height
UBOT | u-component of wind at lowest model level
V | v-component of wind
V10 | v-component of wind at 10m height
VBOT | v-component of wind at lowest model level
VEGFRA | Vegetation fraction

**Daily summaries:**

pcpt | precip
q2 |specific humidity at 2m height
t2min | temperature min
t2 | temperature mean
t2max | temperature max

**References:**

WRF model (Version 3.5)
http://www2.mmm.ucar.edu/wrf/users/wrfv3.5/updates-3.5.1.html

Bieniek, P. A., Bhatt, U. S., Walsh, J. E., Rupp, T. S., Zhang, J., Krieger, J. R., and Lader, R. 2016: Dynamical downscaling of ERA-Interim temperature and precipitation for Alaska. Journal of Applied Meteorology and Climatology, 55(3), 635-654.
https://journals.ametsoc.org/doi/abs/10.1175/JAMC-D-15-0153.1

Lader, R., U. S. Bhatt, J. E. Walsh, T. S. Rupp, and P. A. Bieniek, 2016: 2-m temperature and precipitation from atmospheric reanalysis evaluated for Alaska. J Appl Meteor Climatol, 55, 901-922.
https://journals.ametsoc.org/doi/abs/10.1175/JAMC-D-15-0162.1

Bieniek, P.A., U.S. Bhatt, J.E. Walsh, R. Lader, B. Griffith, J.K. Roach, and R.L. Thoman, 2018: Assessment of Alaska Rain-on-Snow Events Using Dynamical Downscaling.J. Appl. Meteor. Climatol., 57, 1847–1863, https://doi.org/10.1175/JAMC-D-17-0276.1
https://journals.ametsoc.org/doi/10.1175/JAMC-D-17-0276.1

Lader, R., J.E. Walsh, U.S. Bhatt, and P.A. Bieniek, 2017: Projections of Twenty-First-Century Climate Extremes for Alaska via Dynamical Downscaling and Quantile Mapping. J. Appl. Meteor. Climatol., 56, 2393–2409, https://doi.org/10.1175/JAMC-D-16-0415.1
https://journals.ametsoc.org/doi/10.1175/JAMC-D-16-0415.1