Alaska NHM Domain map of permanent snow and initial snowpack depths, derived from monthly-mean GCM Snow water equivalent simulations, January 1980 - October 2022

This data release contains a map of permanent snow, and initial snow-depths for use in NHM-PRMS modeling of the Alaska Domain. Data were computed from NASA's GCM NetCDF files of snow-water equivalent (SWE) monthly-mean data to arrive at values used to initialize the model runs. Grid cells reporting snow were compared between 43 years of monthly-mean NetCDF files. Those gird cells with permanent SWE values were flagged and a map made of this. The resulting data layer shows grid cells in locations of perennial snowfields found in data spanning roughly 43-years (January 1980 through October 2022). Deeper SWE depths coincide with the location of glaciers but do not cover the full extent of glaciers. These data were computed to populate a PRMS hydrologic response unit parameter value for the starting date of January 1, 1980. PRMS is a deterministic, distributed-parameter, physical-process-based modeling system developed to evaluate the response of streamflow and general basin hydrology to various combinations of climate and land use.
CONTENTS OF THIS DATA RELEASE:
1. SWE_metadata.csv = NASA snow-water equivalent product (NetCDF) metadata.
2. FLDAS_glacier_depth_19820101 1.nc = NetCDF file of grid cells showing permanent snow.
3. AK_NHM_perm_snow.zip = AK NHM shapefile of permanent snow.
4.snowpack_init.csv = Result: PRMS HRU parameter values: snowpack_init