Wind-Associated Melt Trends and Contrasts Between the Greenland and Antarctic Ice Sheets

Fohn and katabatic winds (downslope winds) can increase ice sheet surface melt, run-off, and ice-shelf vulnerability to hydrofracture and are poorly constrained on the Greenland and Antarctic ice sheets (GIS and AIS). We use regional climate model simulations of the GIS and AIS to quantify and intercompare trends in downslope winds and associated melt since 1960. Results reveal surface melt associated with downslope wind is significant on both the GIS and AIS representing 27.5 +/- 4.5% and 19.7 +/- 3.8% of total surface melt respectively. Wind-associated melt has decreased 31.8 +/- 5.3% on the AIS while total melt decreased 15.4 +/- 2.4% due to decreased fohn-induced melt on the Antarctic Peninsula and increasing stratospheric ozone. Wind-associated melt has increased 10.3 +/- 2.5% on the GIS, combining with a more positive North Atlantic Oscillation and warmer surface to increase total melt 34 +/- 5.8%.

Automated summary

This study uses climate model simulations to analyze the trends in downslope winds and associated melt on the Greenland and Antarctic ice sheets since 1960. The results show that downslope wind significantly affects surface melt on both ice sheets. The study also reveals a decrease in wind-associated melt on the Antarctic ice sheet, while an increase is observed on the Greenland ice sheet.