Antarctic Peninsula Ice Surface Elevation Change - Preliminary Analysis of CryoSat-2 Data
Briggs, Kate1; Shepherd, A1; McMillan, M1; Ticconi, F1; Muir, A2

The Antarctic Peninsula (AP) has recently experienced rapid climate warming, ice shelf thinning and collapse, accelerated glacier thinning and flow, and widespread retreat of tidewater glaciers. These changes have major implications for the regional ice sheet mass balance and for global sea level rise. Geodetic estimates of the AP Ice Sheet (APIS) mass balance indicate that it lost mass at an average rate of 20 ± 14 Gt/yr over the period 1992-2011 (Shepherd et al., 2012); this equates to approximately 25% of all Antarctic ice sheet mass losses, despite occupying only 4% of the continental area. Continued and comprehensive observations of changes to the APIS are therefore essential.

Data from the CryoSat-2 mission has the potential to offer the first comprehensive satellite altimeter estimate of APIS mass balance. The complex topography and the relatively large number of small glaciological systems that comprise the APIS have, in the past, proven an obstacle to altimetry estimates of its mass balance. However, the fine resolution and densely sampled observations possible from CryoSat-2 will enable reliable measurements of surface elevation change in such regions. Here we present an initial analysis of CryoSat-2 data over the Antarctic Peninsula. We compare the CryoSat-2 elevation measurements to observations acquired by other sensors, including the ICESat and ICEBridge laser altimeter systems. We examine short-term changes in the elevation and volume of the outlet glaciers draining the AP over the period 2010 to 2012 based on the CryoSat-2 data alone, and we provide an assessment of their utility for estimating the AP mass balance. Finally, in regions of rapid thinning, we compare the CryoSat-2 elevation measurements to those acquired by previous missions so as to characterise longer-term changes in ice volume.