Projecting Changes to Northern Hemisphere Snow Resources Under Different Emission Scenarios, Using Google Earth Engine

Abstract:

In this study Northern Hemisphere (NH) snow resources were simulated for the period 1950 – 2100 using the SNOW17 model in Google Earth Engine (GEE). The model was run with the ensemble of the 21 GCMs in the NASA NEX GDDP dataset, for the emission scenarios RCP45 and RCP85. The model was evaluated based on Snow Water Equivalent (SWE) and Snow Cover Area (SCA) data from the GLDAS-2 dataset and SCA remote sensing data from the MODIS/Terra instrument. The results showed extensive changes to the NH cryosphere over the study period. Across the hemisphere snow cover was found to decrease during the period and may disappear completely in many mid-latitude regions. At those latitudes snow melt will contribute less to overall streamflow, whereas further north, many basins will experience an increase in winter SWE. Averaged across the NH the number of snow-covered days annually is expected to decrease by 12.5% and 23.1% between the periods 1950-1975 and 2075-2100, under the RCP45 and RCP85 emissions scenarios, respectively. In contrast, the average winter SWE in the NH expected to increase by 3.9% and 2.2% between the same periods, under the RCP45 an RCP85 emissions scenarios, respectively