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

• Published in: Journal of Glaciology
• Main Authors: Young, Duncan, Greenbaum, J. S., Blankenship, D.D., Lindzey, Laura, Garcia de Gorordo, Alvaro, Kempf, S., Roberts, Jason, Warner, Roland C., van Ommen, Tas, Siegert, Martin, Le Meur, Emmanuel
• Other Authors: Institute for Geophysics, University of Texas at Dallas Richardson (UT Dallas), Laboratory for Atmospheric and Space Physics Boulder (LASP), University of Colorado Boulder, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: AEROGEOPHYSICAL MEASUREMENTS; ANTARCTIC GLACIOLOGY; GLACIER MAPPING; GLACIOLOGICAL INSTRUMENTS AND METHODS; ICE-SHEET MASS BALANCE; [SDU]Sciences of the Universe [physics]; [SDE]Environmental Sciences; Antarctic; Cook Ice Shelf; East Antarctica; The Antarctic; Antarc*; Antarctica; Ice Sheet; Ice Shelf; Journal of Glaciology
• Online Access: https://insu.hal.science/insu-01164726; https://insu.hal.science/insu-01164726/document; https://insu.hal.science/insu-01164726/file/land-ice-elevation-changes-from-photon-counting-swath-altimetry-first-applications-over-the-antarctic-ice-sheet.pdf; https://doi.org/10.3189/2015JoG14J048

International audience 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 altimetry dataset 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 2003–09 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 surface slope and the actual Δz/Δt 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 observe a lack of ice dynamic change at Cook Ice Shelf, while significant thinning occurred at Totten and Denman Glaciers during 2003–09.