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...
Published in: | Climate of the Past |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2015
|
Subjects: | |
Online Access: | https://hdl.handle.net/1956/10385 https://doi.org/10.5194/cp-10-1305-2014 |
id |
ftunivbergen:oai:bora.uib.no:1956/10385 |
---|---|
record_format |
openpolar |
spelling |
ftunivbergen:oai:bora.uib.no:1956/10385 2023-05-15T14:00:18+02:00 Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth Langebroek, Petra Nisancioglu, Kerim Hestnes 2015-07-28T08:46:30Z application/pdf https://hdl.handle.net/1956/10385 https://doi.org/10.5194/cp-10-1305-2014 eng eng Copernicus Publications Norges forskningsråd: 221598 urn:issn:1814-9332 urn:issn:1814-9324 https://hdl.handle.net/1956/10385 https://doi.org/10.5194/cp-10-1305-2014 cristin:1143759 Attribution CC BY http://creativecommons.org/licenses/by/3.0/ Copyright 2014 The Authors Climate of the Past 10 4 1305-1318 VDP::Matematikk og naturvitenskap: 400::Geofag: 450::Meteorologi: 453 VDP::Mathematics and natural scienses: 400::Geosciences: 450::Meteorology: 453 Peer reviewed Journal article 2015 ftunivbergen https://doi.org/10.5194/cp-10-1305-2014 2023-03-14T17:42:38Z 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 University of Bergen: Bergen Open Research Archive (BORA-UiB) Austral Southern Ocean Climate of the Past 10 4 1305 1318 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
VDP::Matematikk og naturvitenskap: 400::Geofag: 450::Meteorologi: 453 VDP::Mathematics and natural scienses: 400::Geosciences: 450::Meteorology: 453 |
spellingShingle |
VDP::Matematikk og naturvitenskap: 400::Geofag: 450::Meteorologi: 453 VDP::Mathematics and natural scienses: 400::Geosciences: 450::Meteorology: 453 Langebroek, Petra Nisancioglu, Kerim Hestnes Simulating last interglacial climate with NorESM: role of insolation and greenhouse gases in the timing of peak warmth |
topic_facet |
VDP::Matematikk og naturvitenskap: 400::Geofag: 450::Meteorologi: 453 VDP::Mathematics and natural scienses: 400::Geosciences: 450::Meteorology: 453 |
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 |
Langebroek, Petra Nisancioglu, Kerim Hestnes |
author_facet |
Langebroek, Petra Nisancioglu, Kerim Hestnes |
author_sort |
Langebroek, Petra |
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 |
2015 |
url |
https://hdl.handle.net/1956/10385 https://doi.org/10.5194/cp-10-1305-2014 |
geographic |
Austral Southern Ocean |
geographic_facet |
Austral Southern Ocean |
genre |
Antarc* Antarctica North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctica North Atlantic Southern Ocean |
op_source |
Climate of the Past 10 4 1305-1318 |
op_relation |
Norges forskningsråd: 221598 urn:issn:1814-9332 urn:issn:1814-9324 https://hdl.handle.net/1956/10385 https://doi.org/10.5194/cp-10-1305-2014 cristin:1143759 |
op_rights |
Attribution CC BY http://creativecommons.org/licenses/by/3.0/ Copyright 2014 The Authors |
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 |
_version_ |
1766269348548182016 |