| 1. |
- Gardner, Alex S., et al.
(författare)
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A Reconciled Estimate of Glacier Contributions to Sea Level Rise : 2003 to 2009
- 2013
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 340:6134, s. 852-857
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Tidskriftsartikel (refereegranskat)abstract
- Glaciers distinct from the Greenland and Antarctic Ice Sheets are losing large amounts of water to the world's oceans. However, estimates of their contribution to sea level rise disagree. We provide a consensus estimate by standardizing existing, and creating new, mass-budget estimates from satellite gravimetry and altimetry and from local glaciological records. In many regions, local measurements are more negative than satellite-based estimates. All regions lost mass during 2003-2009, with the largest losses from Arctic Canada, Alaska, coastal Greenland, the southern Andes, and high-mountain Asia, but there was little loss from glaciers in Antarctica. Over this period, the global mass budget was -259 +/- 28 gigatons per year, equivalent to the combined loss from both ice sheets and accounting for 29 +/- 13% of the observed sea level rise.
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| 2. |
- Kienholz, Christian, et al.
(författare)
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A new semi-automatic approach for dividing glacier complexes into individual glaciers
- 2013
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Ingår i: Journal of Glaciology. - 0022-1430 .- 1727-5652. ; 59:217, s. 925-937
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Tidskriftsartikel (refereegranskat)abstract
- Many glaciological and hydrological studies require outlines of individual glaciers rather than total ice cover. Here we develop a new semi-automatic algorithm that uses a digital elevation model (DEM) and outlines of glacier complexes to calculate the extents of individual glaciers. The algorithm first applies hydrological modeling tools to a modified DEM to calculate flowsheds. It then merges flowsheds that belong to individual glaciers using a distance-based approach, whose required empirical parameters are derived from the Juneau Icefield area in Alaska. In this region, 2% of similar to 1300 glaciers were misclassified. The algorithm was validated on >25 000 km(2) of ice in other regions in Alaska and on >40 000 km(2) of ice in Arctic Canada, resulting in similar to 2% and similar to 3% misclassified glaciers, respectively. Results indicate that the algorithm is robust provided the DEM and the outlines are of good quality.
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