Ice Layers as an Indicator of Summer Warmth and Atmospheric Blocking in Alaska
Samples were collected from a snow pit and shallow urn core near Kahiltna Pass (2970 m a.s.l.), Denali National Park, Alaska, USA, in May 2008. The record spans autumn 2003 to spring 2008 and reveals clusters of ice layers interpreted as summertime intervals of above-freezing temperatures. High corr...
| Main Authors: | , , , |
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| Format: | Text |
| Language: | unknown |
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DigitalCommons@UMaine
2010
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| Subjects: | |
| Online Access: | https://digitalcommons.library.umaine.edu/ers_facpub/48 https://digitalcommons.library.umaine.edu/context/ers_facpub/article/1047/viewcontent/kreutz_56.198.715.pdf |
| Summary: | Samples were collected from a snow pit and shallow urn core near Kahiltna Pass (2970 m a.s.l.), Denali National Park, Alaska, USA, in May 2008. The record spans autumn 2003 to spring 2008 and reveals clusters of ice layers interpreted as summertime intervals of above-freezing temperatures. High correlation coefficients (0.75-1.00) between annual ice-layer thickness and regional summertime station temperatures for 4 years (n=4) indicate ice-layer thickness is a good proxy for mean and extreme summertime temperatures across Alaska, at least over the short period of record. A Rex-block (aka high-over-low) pattern, a downstream trough over Hudson Bay, Canada, and an upstream trough over eastern Siberia occurred during the three melting events that lasted at least 2 weeks. About half of all shorter melting events were associated with a cut-off low traversing the Gulf of Alaska. We hypothesize that a surface-to-bedrock core extracted from this location would provide a high-quality record of summer temperature and atmospheric blocking variability for the last several hundred years. |
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