Late Quaternary glacier sensitivity to temperature and precipitation distribution in the Southern Alps of New Zealand
| Autor: | Mitchell A. Plummer, Simon H. Brocklehurst, Ann V. Rowan, Neil F. Glasser, Leif S. Anderson, David M. Schultz |
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| Rok vydání: | 2014 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Ice stream Glacier Last Glacial Maximum 15. Life on land 010502 geochemistry & geophysics Glacier morphology 01 natural sciences Glacier mass balance Geophysics 13. Climate action Climatology Interglacial Glacial period Precipitation Physical geography Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Journal of Geophysical Research: Earth Surface. 119:1064-1081 |
| ISSN: | 2169-9003 |
| DOI: | 10.1002/2013jf003009 |
| Popis: | Glaciers respond to climate variations and leave geomorphic evidence that represents an important terrestrial paleoclimate record. However, the accuracy of paleoclimate reconstructions from glacial geology is limited by the challenge of representing mountain meteorology in numerical models. Precipitation is usually treated in a simple manner and yet represents difficult-to-characterize variables such as amount, distribution, and phase. Furthermore, precipitation distributions during a glacial probably differed from present-day interglacial patterns. We applied two models to investigate glacier sensitivity to temperature and precipitation in the eastern Southern Alps of New Zealand. A 2-D model was used to quantify variations in the length of the reconstructed glaciers resulting from plausible precipitation distributions compared to variations in length resulting from change in mean annual air temperature and precipitation amount. A 1-D model was used to quantify variations in length resulting from interannual climate variability. Assuming that present-day interglacial values represent precipitation distributions during the last glacial, a range of plausible present-day precipitation distributions resulted in uncertainty in the Last Glacial Maximum length of the Pukaki Glacier of 17.1 km (24%) and the Rakaia Glacier of 9.3 km (25%), corresponding to a 0.5°C difference in temperature. Smaller changes in glacier length resulted from a 50% decrease in precipitation amount from present-day values (−14% and −18%) and from a 50% increase in precipitation amount (5% and 9%). Our results demonstrate that precipitation distribution can produce considerable variation in simulated glacier extents and that reconstructions of paleoglaciers should include this uncertainty. |
| Databáze: | OpenAIRE |
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