Influence of synoptic scale weather variability on ice speed-up events in Southwest Greenland ...

• Main Author: Schmid, Timo
• Format: Text
• Language: English
• Published: ETH Zurich 2021
• Subjects: Greenland ice sheet; Atmospheric dynamics; Glaciology; glacier; Greenland; Ice Sheet
• Online Access: https://dx.doi.org/10.3929/ethz-b-000561596; http://hdl.handle.net/20.500.11850/561596

The Greenland Ice Sheet (GrIS) has experienced increasing ice loss in the past decades and the trend is expected to continue due to climate change. However, large uncertainties about the magnitude of Greenland’s future ice loss remain. One process that contributes to this uncertainty are transient ice accelerations, so-called ice speed-up events, caused by a short-term increase in rain-/meltwater, which descends to the glacier bed and can enhance basal sliding. Here, we investigate this phenomenon focusing on two main objectives. First, we present an analysis of local conditions on the Russell glacier in Southwest Greenland, which confirms the importance of meltwater variability for ice speed-up events. We find the strongest influence in early summer with correlations between surface melt and ice velocities above 0.8 in May and identify a typical lag of zero to one day between meltwater peaks and their ice velocity responses. Contrastingly, we find rainfall to have a minor influence with only 4 out of 51 ice ...