C24A-07
A Decade of Elevation and Mass Changes of the North Atlantic Glaciers and Ice Caps
Tuesday, 15 December 2015: 17:30
3007 (Moscone West)
Bert Wouters1,2, Stefan Ligtenberg3, Geir Moholdt4, Alex S Gardner5, Michiel van den Broeke2 and Jonathan L Bamber1, (1)University of Bristol, Bristol, United Kingdom, (2)Institute for Marine and Atmospheric Research Utrecht, Utrecht, Netherlands, (3)University Utrecht / IMAU, Utrecht, Netherlands, (4)Norwegian Polar Institute, Tromsø, Norway, (5)NASA Jet Propulsion Laboratory, Pasadena, CA, United States
Abstract:
With a dense coverage and the ability to geo-locate the radar echo position, Cryosat-2's altimeter is well suited for determining elevation change rates of ice caps and glaciers that are often characterized by more complex topographic relief than the much larger ice sheets. We determine elevations trends from Cryosat-2 (2010-2014) of the North-Atlantic glaciers and ice caps and compare these to observations obtained from ICESat laser altimetry (2003-2009). The results show a general glacier imbalance with current climate, characterized by rapid thinning at the lower elevations where surface melting is stronger. Using a firn and surface mass balance model, we estimate the contribution of the North Atlantic glaciers to sea level rise over the 2003-2014 period to be ~ 1/3 mm per year. In general, our altimetry results are in good agreement with large-scale glacier mass anomalies from GRACE. Regional glacier mass changes appear to be linked to distinct atmospheric circulation patterns, with some regions being in ‘status quo' and others experiencing rapid shrinkage. Regional changes in elevation are primarily driven by changes in surface forcing with glacier dynamics dominating the local signal of several tidewater basins.
