Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth
The last interglacial (LIG, ~130–116 ka, ka = 1000 yr ago) is characterized by high-latitude warming and is therefore often considered as a possible analogue for future warming. However, in contrast to predicted future greenhouse warming, the LIG climate is largely governed by variations in insolati...
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ftdoajarticles:oai:doaj.org/article:20bcc30306894e96af29dbe28438f334 2023-05-15T14:05:31+02:00 Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth P.M. Langebroek K. H. Nisancioglu 2014-07-01T00:00:00Z https://doi.org/10.5194/cp-10-1305-2014 https://doaj.org/article/20bcc30306894e96af29dbe28438f334 EN eng Copernicus Publications http://www.clim-past.net/10/1305/2014/cp-10-1305-2014.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 doi:10.5194/cp-10-1305-2014 https://doaj.org/article/20bcc30306894e96af29dbe28438f334 Climate of the Past, Vol 10, Iss 4, Pp 1305-1318 (2014) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2014 ftdoajarticles https://doi.org/10.5194/cp-10-1305-2014 2022-12-31T14:03:29Z The last interglacial (LIG, ~130–116 ka, ka = 1000 yr ago) is characterized by high-latitude warming and is therefore often considered as a possible analogue for future warming. However, in contrast to predicted future greenhouse warming, the LIG climate is largely governed by variations in insolation. Greenhouse gas (GHG) concentrations were relatively stable and similar to pre-industrial values, with the exception of the early LIG when, on average, GHGs were slightly lower. We performed six time-slice simulations with the low-resolution version of the Norwegian Earth System Model covering the LIG. In four simulations only the orbital forcing was changed. In two other simulations, representing the early LIG, additionally the GHG forcing was reduced. With these simulations we investigate (1) the different effects of GHG versus insolation forcing on the temperatures during the LIG; (2) whether reduced GHGs can explain the low temperatures reconstructed for the North Atlantic; and (3) the timing of the observed LIG peak warmth. Our simulations show that the insolation forcing results in seasonal and hemispheric differences in temperature. In contrast, a reduction in the GHG forcing causes a global and seasonal-independent cooling. Furthermore, we compare modelled temperatures with proxy-based LIG sea-surface temperatures along a transect in the North Atlantic. The modelled North Atlantic summer sea-surface temperatures capture the general trend of the reconstructed summer temperatures, with low values in the early LIG, a peak around 125 ka, and a steady decrease towards the end of the LIG. Simulations with reduced GHG forcing improve the model–data fit as they show lower temperatures in the early LIG. Furthermore we show that the timing of maximum summer and winter surface temperatures is in line with the local summer and winter insolation maximum at most latitudes. Two regions where the maximum local insolation and temperature do not occur at the same time are Antarctica and the Southern Ocean. The austral summer ... Article in Journal/Newspaper Antarc* Antarctica North Atlantic Southern Ocean Directory of Open Access Journals: DOAJ Articles Southern Ocean Austral Climate of the Past 10 4 1305 1318 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 P.M. Langebroek K. H. Nisancioglu Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
The last interglacial (LIG, ~130–116 ka, ka = 1000 yr ago) is characterized by high-latitude warming and is therefore often considered as a possible analogue for future warming. However, in contrast to predicted future greenhouse warming, the LIG climate is largely governed by variations in insolation. Greenhouse gas (GHG) concentrations were relatively stable and similar to pre-industrial values, with the exception of the early LIG when, on average, GHGs were slightly lower. We performed six time-slice simulations with the low-resolution version of the Norwegian Earth System Model covering the LIG. In four simulations only the orbital forcing was changed. In two other simulations, representing the early LIG, additionally the GHG forcing was reduced. With these simulations we investigate (1) the different effects of GHG versus insolation forcing on the temperatures during the LIG; (2) whether reduced GHGs can explain the low temperatures reconstructed for the North Atlantic; and (3) the timing of the observed LIG peak warmth. Our simulations show that the insolation forcing results in seasonal and hemispheric differences in temperature. In contrast, a reduction in the GHG forcing causes a global and seasonal-independent cooling. Furthermore, we compare modelled temperatures with proxy-based LIG sea-surface temperatures along a transect in the North Atlantic. The modelled North Atlantic summer sea-surface temperatures capture the general trend of the reconstructed summer temperatures, with low values in the early LIG, a peak around 125 ka, and a steady decrease towards the end of the LIG. Simulations with reduced GHG forcing improve the model–data fit as they show lower temperatures in the early LIG. Furthermore we show that the timing of maximum summer and winter surface temperatures is in line with the local summer and winter insolation maximum at most latitudes. Two regions where the maximum local insolation and temperature do not occur at the same time are Antarctica and the Southern Ocean. The austral summer ... |
format |
Article in Journal/Newspaper |
author |
P.M. Langebroek K. H. Nisancioglu |
author_facet |
P.M. Langebroek K. H. Nisancioglu |
author_sort |
P.M. Langebroek |
title |
Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth |
title_short |
Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth |
title_full |
Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth |
title_fullStr |
Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth |
title_full_unstemmed |
Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth |
title_sort |
simulating last interglacial climate with noresm: role of insolation and greenhouse gases in the timing of peak warmth |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/cp-10-1305-2014 https://doaj.org/article/20bcc30306894e96af29dbe28438f334 |
geographic |
Southern Ocean Austral |
geographic_facet |
Southern Ocean Austral |
genre |
Antarc* Antarctica North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctica North Atlantic Southern Ocean |
op_source |
Climate of the Past, Vol 10, Iss 4, Pp 1305-1318 (2014) |
op_relation |
http://www.clim-past.net/10/1305/2014/cp-10-1305-2014.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 doi:10.5194/cp-10-1305-2014 https://doaj.org/article/20bcc30306894e96af29dbe28438f334 |
op_doi |
https://doi.org/10.5194/cp-10-1305-2014 |
container_title |
Climate of the Past |
container_volume |
10 |
container_issue |
4 |
container_start_page |
1305 |
op_container_end_page |
1318 |
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1766277478504988672 |