Direct measurements of firn-density evolution from 2016 to 2022 at Wolverine Glacier, Alaska
Knowledge of snow and firn-density change is needed to use elevation-change measurements to estimate glacier mass change. Additionally, firn-density evolution on glaciers is closely connected to meltwater percolation, refreezing and runoff, which are key processes for glacier mass balance and hydrol...
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2024-01-01
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| Series: | Journal of Glaciology |
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| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143024000248/type/journal_article |
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| author | C. Max Stevens Louis Sass Caitlyn Florentine Christopher McNeil Emily Baker Katherine Bollen |
| author_facet | C. Max Stevens Louis Sass Caitlyn Florentine Christopher McNeil Emily Baker Katherine Bollen |
| author_sort | C. Max Stevens |
| collection | DOAJ |
| description | Knowledge of snow and firn-density change is needed to use elevation-change measurements to estimate glacier mass change. Additionally, firn-density evolution on glaciers is closely connected to meltwater percolation, refreezing and runoff, which are key processes for glacier mass balance and hydrology. Since 2016, the U.S. Geological Survey Benchmark Glacier Project has recovered firn cores from a site on Wolverine Glacier in Alaska's Kenai Mountains. We use annual horizons in repeat cores to track firn densification and meltwater retention over seasonal and interannual timescales, and we use density measurements to quantify how the firn air content (FAC) changes through time. The results suggest the firn is densifying due primarily to compaction rather than refreezing. Liquid-water retention in the firn is transient, likely due to gravity-fed drainage and irreducible-water-content decreases that accompany decreasing porosity. We show that the uncertainty (±60 kg m−3) in the commonly used volume-to-mass conversion factor of 850 kg m−3 is an underestimation when glacier-wide FAC variability exceeds 12% of the glacier-averaged height change. Our results demonstrate how direct measurements of firn properties on mountain glaciers can be used to better quantify the uncertainty in geodetic volume-to-mass conversions. |
| format | Article |
| id | doaj-art-15ff81bf472643d2aaca95e02d363d8c |
| institution | Kabale University |
| issn | 0022-1430 1727-5652 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj-art-15ff81bf472643d2aaca95e02d363d8c2025-01-16T21:47:42ZengCambridge University PressJournal of Glaciology0022-14301727-56522024-01-017010.1017/jog.2024.24Direct measurements of firn-density evolution from 2016 to 2022 at Wolverine Glacier, AlaskaC. Max Stevens0https://orcid.org/0000-0003-2005-0876Louis Sass1https://orcid.org/0000-0003-4677-029XCaitlyn Florentine2https://orcid.org/0000-0002-7028-0963Christopher McNeil3https://orcid.org/0000-0003-4170-0428Emily Baker4https://orcid.org/0000-0002-0938-3496Katherine Bollen5https://orcid.org/0000-0003-4345-0899U.S. Geological Survey, Northern Rocky Mountain Science Center, West Glacier, MT, USAU.S. Geological Survey, Alaska Science Center, Anchorage, AK, USAU.S. Geological Survey, Northern Rocky Mountain Science Center, West Glacier, MT, USAU.S. Geological Survey, Alaska Science Center, Anchorage, AK, USAU.S. Geological Survey, Alaska Science Center, Anchorage, AK, USAU.S. Geological Survey, Alaska Science Center, Anchorage, AK, USAKnowledge of snow and firn-density change is needed to use elevation-change measurements to estimate glacier mass change. Additionally, firn-density evolution on glaciers is closely connected to meltwater percolation, refreezing and runoff, which are key processes for glacier mass balance and hydrology. Since 2016, the U.S. Geological Survey Benchmark Glacier Project has recovered firn cores from a site on Wolverine Glacier in Alaska's Kenai Mountains. We use annual horizons in repeat cores to track firn densification and meltwater retention over seasonal and interannual timescales, and we use density measurements to quantify how the firn air content (FAC) changes through time. The results suggest the firn is densifying due primarily to compaction rather than refreezing. Liquid-water retention in the firn is transient, likely due to gravity-fed drainage and irreducible-water-content decreases that accompany decreasing porosity. We show that the uncertainty (±60 kg m−3) in the commonly used volume-to-mass conversion factor of 850 kg m−3 is an underestimation when glacier-wide FAC variability exceeds 12% of the glacier-averaged height change. Our results demonstrate how direct measurements of firn properties on mountain glaciers can be used to better quantify the uncertainty in geodetic volume-to-mass conversions.https://www.cambridge.org/core/product/identifier/S0022143024000248/type/journal_articleglacier mass balancemountain glacierspolar firnsnow/ice surface processessurface mass budget |
| spellingShingle | C. Max Stevens Louis Sass Caitlyn Florentine Christopher McNeil Emily Baker Katherine Bollen Direct measurements of firn-density evolution from 2016 to 2022 at Wolverine Glacier, Alaska Journal of Glaciology glacier mass balance mountain glaciers polar firn snow/ice surface processes surface mass budget |
| title | Direct measurements of firn-density evolution from 2016 to 2022 at Wolverine Glacier, Alaska |
| title_full | Direct measurements of firn-density evolution from 2016 to 2022 at Wolverine Glacier, Alaska |
| title_fullStr | Direct measurements of firn-density evolution from 2016 to 2022 at Wolverine Glacier, Alaska |
| title_full_unstemmed | Direct measurements of firn-density evolution from 2016 to 2022 at Wolverine Glacier, Alaska |
| title_short | Direct measurements of firn-density evolution from 2016 to 2022 at Wolverine Glacier, Alaska |
| title_sort | direct measurements of firn density evolution from 2016 to 2022 at wolverine glacier alaska |
| topic | glacier mass balance mountain glaciers polar firn snow/ice surface processes surface mass budget |
| url | https://www.cambridge.org/core/product/identifier/S0022143024000248/type/journal_article |
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