Acknowledgements. Countless individuals helped with fieldwork and historical data reduction. We are particularly appreciative of program maintenance from Mark Meier, Bob Krimmel, Larry Mayo, Dennis Trabant and Rod March. Recently Adam Clark, Erin Whorton and Zach Miller provided invaluable assistance with field and data preparation. Thanks to the Juneau Icefield Research Program for data sharing, access and collaboration, in particular to Mauri Pelto for guiding us through the history of data collection by JIRP. Comments from Jack Kohler, Liam Colgan, Mike Loso and an anonymous reviewer greatly improved the manuscript. Funding for the work came from USGS under the guise of many programs throughout the years. Today, support is granted by the Land Resources Mission Area, Climate Research and Development Program. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the US Government.
Journal of Glaciology
Glacier mass balance, Glaciers -- Environmental aspects
Mountain glaciers integrate climate processes to provide an unmatched signal of regional climate forcing. However, extracting the climate signal via intercomparison of regional glacier mass-balance records can be problematic when methods for extrapolating and calibrating direct glaciological measurements are mixed or inconsistent. To address this problem, we reanalyzed and compared long-term mass-balance records from the US Geological Survey Benchmark Glaciers. These five glaciers span maritime and continental climate regimes of the western United States and Alaska. Each glacier exhibits cumulative mass loss since the mid-20th century, with average rates ranging from −0.58 to −0.30 m w.e. a−1. We produced a set of solutions using different extrapolation and calibration methods to inform uncertainty estimates, which range from 0.22 to 0.44 m w.e. a−1. Mass losses are primarily driven by increasing summer warming. Continentality exerts a stronger control on mass loss than latitude. Similar to elevation, topographic shading, snow redistribution and glacier surface features often exert important mass-balance controls. The reanalysis underscores the value of geodetic calibration to resolve mass-balance magnitude, as well as the irreplaceable value of direct measurements in contributing to the process-based understanding of glacier mass balance.
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O'Neel, S., McNeil, C., Sass, L. C., Florentine, C., Baker, E. H., Peitzsch, E., ... & Fagre, D. (2019). Reanalysis of the US Geological Survey Benchmark Glaciers: long-term insight into climate forcing of glacier mass balance. Journal of Glaciology, 65(253), 850-866.