Orbital and freshwater forcing during the last interglacial: analysis of climate and vegetation response patterns
Large-scale atmospheric patterns are examined on orbital timescales using the ECHO-G which explicitly resolves the atmosphere – ocean – sea ice dynamics. It is shown that in contrast to boreal summer where the climate mainly follows the local radiative forcing, the boreal winter climate is strongly...
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fttriple:oai:gotriple.eu:10670/1.eob3ji 2023-05-15T15:06:33+02:00 Orbital and freshwater forcing during the last interglacial: analysis of climate and vegetation response patterns Lohmann, G. 2018-09-26 https://doi.org/10.5194/cpd-2-1221-2006 https://cp.copernicus.org/preprints/cpd-2006-0060/ en eng doi:10.5194/cpd-2-1221-2006 10670/1.eob3ji https://cp.copernicus.org/preprints/cpd-2006-0060/ undefined Geographica Helvetica - geography eISSN: 1814-9332 envir geo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ 2018 fttriple https://doi.org/10.5194/cpd-2-1221-2006 2023-01-22T18:20:00Z Large-scale atmospheric patterns are examined on orbital timescales using the ECHO-G which explicitly resolves the atmosphere – ocean – sea ice dynamics. It is shown that in contrast to boreal summer where the climate mainly follows the local radiative forcing, the boreal winter climate is strongly determined by modulation of the atmospheric circulation. We find that during a positive phase of the Arctic Oscillation/North Atlantic Oscillation the convection in the tropical Pacific is below normal. The atmospheric circulation patterns induce non-uniform temperature anomalies, much stronger in amplitude than by the direct solar insolation. Together with the direct solar insolation this provides for a temperature drop over the Northern Hemisphere continents for 115 000 years before present, large areas over northern Asia and Alaska become a desert, and the grass land expanded to the north. The spatial pattern of temperature and vegetation changes differs from a more hemisphere-wide cooling, i.e. induced by oceanic freshwater in the northern North Atlantic. The signatures of different forcing mechanisms are important for the interpretation of proxy data as well as for the understanding of underlying mechanisms at the end of the last interglacial. Text Arctic North Atlantic North Atlantic oscillation Sea ice Alaska Unknown Arctic Pacific |
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envir geo Lohmann, G. Orbital and freshwater forcing during the last interglacial: analysis of climate and vegetation response patterns |
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envir geo |
description |
Large-scale atmospheric patterns are examined on orbital timescales using the ECHO-G which explicitly resolves the atmosphere – ocean – sea ice dynamics. It is shown that in contrast to boreal summer where the climate mainly follows the local radiative forcing, the boreal winter climate is strongly determined by modulation of the atmospheric circulation. We find that during a positive phase of the Arctic Oscillation/North Atlantic Oscillation the convection in the tropical Pacific is below normal. The atmospheric circulation patterns induce non-uniform temperature anomalies, much stronger in amplitude than by the direct solar insolation. Together with the direct solar insolation this provides for a temperature drop over the Northern Hemisphere continents for 115 000 years before present, large areas over northern Asia and Alaska become a desert, and the grass land expanded to the north. The spatial pattern of temperature and vegetation changes differs from a more hemisphere-wide cooling, i.e. induced by oceanic freshwater in the northern North Atlantic. The signatures of different forcing mechanisms are important for the interpretation of proxy data as well as for the understanding of underlying mechanisms at the end of the last interglacial. |
format |
Text |
author |
Lohmann, G. |
author_facet |
Lohmann, G. |
author_sort |
Lohmann, G. |
title |
Orbital and freshwater forcing during the last interglacial: analysis of climate and vegetation response patterns |
title_short |
Orbital and freshwater forcing during the last interglacial: analysis of climate and vegetation response patterns |
title_full |
Orbital and freshwater forcing during the last interglacial: analysis of climate and vegetation response patterns |
title_fullStr |
Orbital and freshwater forcing during the last interglacial: analysis of climate and vegetation response patterns |
title_full_unstemmed |
Orbital and freshwater forcing during the last interglacial: analysis of climate and vegetation response patterns |
title_sort |
orbital and freshwater forcing during the last interglacial: analysis of climate and vegetation response patterns |
publishDate |
2018 |
url |
https://doi.org/10.5194/cpd-2-1221-2006 https://cp.copernicus.org/preprints/cpd-2006-0060/ |
geographic |
Arctic Pacific |
geographic_facet |
Arctic Pacific |
genre |
Arctic North Atlantic North Atlantic oscillation Sea ice Alaska |
genre_facet |
Arctic North Atlantic North Atlantic oscillation Sea ice Alaska |
op_source |
Geographica Helvetica - geography eISSN: 1814-9332 |
op_relation |
doi:10.5194/cpd-2-1221-2006 10670/1.eob3ji https://cp.copernicus.org/preprints/cpd-2006-0060/ |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cpd-2-1221-2006 |
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1766338128951377920 |