1. Statistically downscaled temperature, precipitation, and derived snow variables
1.1. Temperature
• Average of 5 statistically downscaled climate models: MRI-CGCM3, GISS-E2-R, GFDL-CM3, IPSL-CM5A-LR and NCAR-CCSM4, bias corrected
• Annual; winter (DJF); spring (MAM); summer (JJA); autumn (SON)
• 771m resolution (Alaska wide)
• Original data in degrees C; summary graphics and tables are presented as climatology “deltas” in both degrees C and degrees F, changes (for the period 2040-2069 and 2070-2099) relative to historical (1970-1999)
• RCP 4.5 and RCP8.5
• Details: Walsh et al. 2018
1.2. Precipitation
• Average of 5 statistically downscaled climate models: MRI-CGCM3, GISS-E2-R, GFDL-CM3, IPSL-CM5A-LR and NCAR-CCSM4 , bias corrected
• Annual; winter (DJF); spring (MAM); summer (JJA); autumn (SON)
• 771m resolution (Alaska wide)
• Graphics are presented as climatology “deltas” in percent change in total, changes (for the period 2040-2069 and 2070-2099) relative to historical (1970-1999)
• Details: Walsh et al. 2018
1.3. Snowfall water equivalent
• Average of 5 statistically downscaled climate models: MRI-CGCM3, GISS-E2-R, GFDL-CM3, IPSL-CM5A-LR and NCAR-CCSM4, bias corrected
• Total snowfall water equivalent for October to March
• 771m resolution (Alaska wide)
• Graphics are presented as climatology “deltas” in percent, changes (for the period 2040-2069 and 2070-2099) relative to historical (1970-1999)
• RCP 4.5 and RCP8.5
• Details: Littell et al. 2018
1.4. Snow index
• Average of 5 statistically downscaled climate models: MRI-CGCM3, GISS-E2-R, GFDL-CM3, IPSL-CM5A-LR and NCAR-CCSM4 , bias corrected
• Ratio of snowfall water equivalent to total October-March precipitation, equivalent to the fraction of total October to March precipitation entrained in snowfall water equivalent
• 771m resolution (Alaska wide)
• Graphics are presented as climatology “deltas”, changes (for the period 2040-2069 and 2070-2099) relative to historical (1970-1999)
• RCP 4.5 and RCP8.5
• Details: Littell et al. 2018
1.5. Change in months of reliable snow
• Average of 5 statistically downscaled climate models: MRI-CGCM3, GISS-E2-R, GFDL-CM3, IPSL-CM5A-LR and NCAR-CCSM4, bias corrected
• Change in count of months with >70% precipitation as snow
• 771m resolution (Alaska wide)
• Graphics are presented as climatology “deltas”, changes (for the period 2040-2069) relative to historical (1970-1999)
• Only RCP8.5
2. Derived land surface variables consistent with temperature and precipitation above
2.1. Changes in fires per century, ALFRESCO landscape fire model
• MRI-CGCM3 (lower fire activity) and NCAR-CCSM4 (higher fire activity)
• Change (difference) between 1900-1999 and 2000-2099 fires per model pixel, derived from raw “relative flammability”, or the count of model replicate fires per pixel per time period
• 2km resolution (Alaska and NW Canada)
• Graphics are presented as “deltas” changes (for the 21st century relative to historical 20th century) in fires per century
• RCP4.5 and RCP8.5
• Details: McGuire et al. 2018, Euskirchen et al. 2020
2.2. Changes in vegetation per century, ALFRESCO landscape fire model
• MRI-CGCM3 (lower fire activity) and NCAR-CCSM4 (higher fire activity)
• Change (difference) between 1900-1999 and 2000-2099 vegetation changes per model pixel
• 2km resolution (Alaska and NW Canada)
• Graphics are presented as “deltas” changes (for the 21st century relative to historical 20th century) in vegetation type per century
• RCP4.5 and RCP8.5
• Details: McGuire et al. 2018, Euskirchen et al. 2020
2.3. New Picea glauca (white spruce) establishment, ALFRESCO landscape fire model
• MRI-CGCM3 (lower fire activity) and NCAR-CCSM4 (higher fire activity)
• New spruce colonization in 2050 and 2100 in areas without spruce in historical vegetation map.
• 2km resolution (Alaska and NW Canada)
• Graphics are presented as new establishment at two densities, basal area 0-5m^2/ha for 2050 and 2100 and 5-12m^2/ha for 2050
• Only RCP8.5
• Details: McGuire et al. 2018, Euskirchen et al. 2020
3. TerraClimate hydrologic changes
3.1. Change in spring runoff
• CMIP5 climate model ensemble of deltas at global warming levels (see below)
• Change in volume of monthly total runoff (Q) per pixel relative to historical (1981-2010) for Feb, Mar, Apr, May
• 4km resolution (global, subset for Alaska region)
• Graphics are presented as change (difference) mm of total Q from historical reference
• No emissions, +2C and +4C global warming levels
• Details: Abatzoglou et al. 2018
3.2. Change in summer (JJA) and growing season (AMJJAS) potential evapotranspiration
• CMIP5 climate model ensemble of deltas at global warming levels (see below)
• Change in volume of summer and growing season total potential evapotranspiration (PET) per pixel relative to historical (1981-2010) for Jun-Aug and Apr-Sep
• 4km resolution (global, subset for Alaska region)
• Graphics are presented as change (difference) mm of total PET from historical reference
• No emissions, +2C and +4C global warming levels
• Details: Abatzoglou et al. 2018
3.3. Change in summer (JJA) and growing season (AMJJAS) water balance deficit
• CMIP5 climate model ensemble of deltas at global warming levels (see below)
• Change in volume of summer and growing season total potential evapotranspiration (PET) minus actual evapotranspiration (AET) per pixel relative to historical (1981-2010) for Jun-Aug and Apr-Sep
• 4km resolution (global, subset for Alaska region)
• Graphics are presented as change (difference) mm of total PET-AET from historical reference
• No emissions, +2C and +4C global warming levels
• Details: Abatzoglou et al. 2018