Land-ice elevation changes from photon-counting swath altimetry: first applications over the Antarctic ice sheet

• Published in: Journal of Glaciology
• Main Authors: Young, DA, Lindzey, LE, Blankenship, DD, Greenbaum, JS, Garcia de Gorordo, A, Kempf, SD, Roberts, JL, Warner, RC, van Ommen, T, Siegert, MJ, Le Meur, E
• Format: Article in Journal/Newspaper
• Language: English
• Published: Int Glaciol Soc 2015
• Subjects: Earth Sciences; Oceanography; Physical Oceanography; Antarctic; Cook Ice Shelf; East Antarctica; The Antarctic; Antarc*; Antarctica; Ice Sheet; Ice Shelf; Journal of Glaciology
• Online Access: https://doi.org/10.3189/2015JoG14J048; http://ecite.utas.edu.au/100450

Satellite altimetric time series allow high-precision monitoring of ice-sheet mass balance. Understanding elevation changes in these regions is important because outlet glaciers along ice-sheet margins are critical in controlling flow of inland ice. Here we discuss a new airborne altimetrydataset collected as part of the ICECAP (International Collaborative Exploration of the Cryosphere by Airborne Profiling) project over East Antarctica. Using the ALAMO (Airborne Laser Altimeter with Mapping Optics) system of a scanning photon-counting lidar combined with a laser altimeter,we extend the 200309 surface elevation record of NASA's ICESat satellite, by determining cross-track slope and thus independently correcting for ICESat's cross-track pointing errors. In areas of high slope, cross-track errors result in measured elevation change that combines surfaceslope and the actual Δ z /Δ t signal. Slope corrections are particularly important in coastal ice streams, which often exhibit both rapidly changing elevations and high surface slopes. As a test case (assuming that surface slopes do not change significantly) we observea lack of ice dynamic change at Cook Ice Shelf, while significant thinning occurred at Totten and Denman Glaciers during 200309.