کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6446510 | 1640798 | 2016 | 16 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Constraint on the penultimate glacial maximum Northern Hemisphere ice topography (â140Â kyrs BP)
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
زمین شناسی
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چکیده انگلیسی
The penultimate glacial maximum (PGM, â140Â kyrs BP), is known to be the most extensive glaciation on record that occurred during the last 400Â kyrs over Eurasia. We used a coupled Atmosphere-Ocean-Sea-Ice-Land model to simulate the climate of the PGM accounting for a reconstruction of the large PGM Eurasian ice sheet. Due to uncertainties in the PGM Laurentide ice-sheet topography, two simulations with different ice-sheet topographies over North America (large as for the Last Glacial Maximum, LGM and small as for 13Â kyrs BP) are performed. Results show that the simulated PGM glacial maximum climates are of comparable magnitude with previous simulations of the LGM in both cases. Assuming a small Laurentide ice-sheet instead of the LGM one in our PGM simulations results in a shift in the planetary waves. This causes an increase in storm track activity over the North Atlantic as well as higher temperatures and precipitation rates over North America, North Atlantic and over the Eurasian ice sheet. In addition, it induces a negative temperature anomaly over East Siberia yielding a thick snow cover, which seems to be in agreement with data from recent Arctic campaigns suggesting that an ice cap developed over Beringia during the PGM. All together, the changes in large-scale circulation and regional climate simulated using a small Laurentide ice sheet match the proxies well. Based on our findings, we suggest that the Laurentide ice sheet might have been smaller during the PGM than during the LGM, in turn also implying a larger Eurasian ice sheet than during the LGM, which is supported by various geological evidence of the PGM.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Quaternary Science Reviews - Volume 137, 1 April 2016, Pages 97-112
Journal: Quaternary Science Reviews - Volume 137, 1 April 2016, Pages 97-112
نویسندگان
Florence Colleoni, Claudia Wekerle, Jens-Ove Näslund, Jenny Brandefelt, Simona Masina,