Arctic warming induced by the Laurentide Ice Sheet topography
| Autor: | Johan Liakka, Marcus Lofverstrom |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
lcsh:GE1-350
Global and Planetary Change geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Atmospheric circulation lcsh:Environmental protection Stratigraphy Elevation Paleontology Energy flux Last Glacial Maximum Albedo 010502 geochemistry & geophysics 01 natural sciences lcsh:Environmental pollution Arctic Climatology lcsh:TD172-193.5 lcsh:TD169-171.8 Glacial period Ice sheet lcsh:Environmental sciences Geology 0105 earth and related environmental sciences |
| Zdroj: | Climate of the Past, Vol 14, Pp 887-900 (2018) |
| ISSN: | 1814-9332 |
| Popis: | It is well known that ice sheet–climate feedbacks are essential for realistically simulating the spatiotemporal evolution of continental ice sheets over glacial–interglacial cycles. However, many of these feedbacks are dependent on the ice sheet thickness, which is poorly constrained by proxy data records. For example, height estimates of the Laurentide Ice Sheet (LIS) topography at the Last Glacial Maximum (LGM; ∼ 21 000 years ago) vary by more than 1 km among different ice sheet reconstructions. In order to better constrain the LIS elevation it is therefore important to understand how the mean climate is influenced by elevation discrepancies of this magnitude. Here we use an atmospheric circulation model coupled to a slab-ocean model to analyze the LGM surface temperature response to a broad range of LIS elevations (from 0 to over 4 km). We find that raising the LIS topography induces a widespread surface warming in the Arctic region, amounting to approximately 1.5 ∘C per km of elevation increase, or about 6.5 ∘C for the highest LIS. The warming is attributed to an increased poleward energy flux by atmospheric stationary waves, amplified by surface albedo and water vapor feedbacks, which account for about two-thirds of the total temperature response. These results suggest a strong feedback between continental-scale ice sheets and the Arctic temperatures that may help constrain LIS elevation estimates for the LGM and explain differences in ice distribution between the LGM and earlier glacial periods. |
| Databáze: | OpenAIRE |
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