Projected changes to Northern Hemisphere snow conditions over the period 1950–2100, given two emission scenarios

Abstract

In this study Northern Hemisphere (NH) snow conditions were simulated and analyzed for the period 1950–2100 under two emission scenarios RCP45 and RCP85. Daily snow conditions were simulated using the Snow17 model run on the Google Earth Engine (GEE) parallel cloud computing platform with each of the 21 GCMs in the NASA NEX GDDP dataset. 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 that both NH SWE and the number of Snow-Covered Days (SCD) have and will continue to decrease at lower latitudes, whereas in many high latitude regions SWE is expected to increase, even as SCD is decreasing. The average annual NH SCD is expected to decrease by 12.5% and 23.1% between the periods 1950–1975 and 2075–2100, under RCP45 and RCP85, respectively. Between the same periods however, the NH mean winter SWE is expected to increase slightly in the beginning of the period under both RCPs. By 2100, SWE will have reduced to the 1950–1975 level under RCP45. Under RCP85, SWE will be 10% lower than the 1950–1975 level. These changes will pose a great challenge for water resource management across a wide spectrum, including impacting current way of living.