Spatiotemporal mapping of a large mountain glacier from CryoSat-2 altimeter data: surface elevation and elevation change of Bering Glacier during surge (2011–2014)

ABSTRACT

CryoSat-2 radar altimeter data have been applied to map surface elevations of the Greenland and Antarctic ice sheets, and of Arctic icecaps. In this article we investigate the feasibility of using CryoSat-2 data for spatiotemporal analysis of surface elevation of a large mountain glacier. Bering Glacier, Alaska (which is 8–20 km wide and approximately 80 km long) is selected as a study area because it surges and hence shows short-term elevation changes. The approach includes a correction method, geostatistical analysis, and several methods for error assessment. A time series of digital elevation models (DEMs) is derived for six-month increments from Summer 2011 to Winter 2013/2014. DEMs have, on average, numerical Kriging errors of 1.65 + 3.19 m and Kriging estimation standard deviations of 11.32 + 1.01 m. A crossover analysis with airborne laser altimeter data from the fall months of 2011, 2012, and 2013 produced differences of 5.03 + 13.67 m compared to respective CryoSat-2 data sets. Difference maps are derived from the DEMs and are used to infer dynamical changes associated with the recent surge. In conclusion, CryoSat-2 data can be employed for spatiotemporal mapping of the evolution of surface elevation in Bering Glacier and other mountain glaciers of similar width, while providing key insight into large-scale elevation change over relatively short time periods.

Acknowledgements

Thanks are due to Brian McDonald, CU Boulder, for help with data processing, and to Enrica Cocco, EO Help Desk, for discussion of cross-track geolocation and phase-wrapping errors of CryoSat-2 data. Support for this work through U.S. National Science Foundation Arctic Natural Sciences Awards “RAPID Bering Glacier Surge 2011: Observation, Analysis and Parametrization” (NSF-ANS 1548462), “Bering Glacier Research Experience for Undergraduates” (NSF-ANS 1549750), NSF Geography and Spatial Sciences Award “A Surge in a Complex Glacier System: Results from Observations, Data Analysis and Numerical Experiments of the Bering-Bagley Glacier System” (NSF-GSS 1553133), and NASA Cryospheric Sciences Award “Study of Glacial Acceleration Types Through Innovative Approaches to CryoSat-2, ICESat Operation IceBridge and Other Altimeter Data Analysis” (NNX15AC73G) is gratefully acknowledged. Airborne ULS data collected during the Bering Glacier RAPID project are available via ACADIS at https://www.aoncadis.org/project/Bering_Glacier_Surge.html.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by U.S. National Science Foundation Arctic Natural Sciences Awards “RAPID Bering Glacier Surge 2011: Observation, Analysis and Parametrization” [NSF-ANS 1548462], “Bering Glacier Research Experience for Undergraduates” [NSF-ANS 1549750], NSF Geography and Spatial Sciences Award “A Surge in a Complex Glacier System: Results from Observations, Data Analysis and Numerical Experiments of the Bering-Bagley Glacier System” [NSF-GSS 1553133], and NASA Cryospheric Sciences Award “Study of Glacial Acceleration Types Through Innovative Approaches to CryoSat-2, ICESat Operation IceBridge and Other Altimeter Data Analysis” [NNX15AC73G].