Simulating low frequency changes in atmospheric CO 2 during the last 740 000 years
Atmospheric CO 2 measured in Antarctic ice cores shows a natural variability of 80 to 100 ppmv during the last four glacial cycles and variations of approximately 60 ppmv in the two cycles between 410 and 650 kyr BP. We here use various paleo-climatic records from the EPICA Dome C Antarctic ice core...
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ftdoajarticles:oai:doaj.org/article:306eab155c1a435fa721295569a51a2c 2023-05-15T14:03:49+02:00 Simulating low frequency changes in atmospheric CO 2 during the last 740 000 years P. Köhler H. Fischer 2006-01-01T00:00:00Z https://doaj.org/article/306eab155c1a435fa721295569a51a2c EN eng Copernicus Publications http://www.clim-past.net/2/57/2006/cp-2-57-2006.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 https://doaj.org/article/306eab155c1a435fa721295569a51a2c Climate of the Past, Vol 2, Iss 2, Pp 57-78 (2006) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2006 ftdoajarticles 2022-12-31T12:29:36Z Atmospheric CO 2 measured in Antarctic ice cores shows a natural variability of 80 to 100 ppmv during the last four glacial cycles and variations of approximately 60 ppmv in the two cycles between 410 and 650 kyr BP. We here use various paleo-climatic records from the EPICA Dome C Antarctic ice core and from oceanic sediment cores covering the last 740 kyr to force the ocean/atmosphere/biosphere box model of the global carbon cycle BICYCLE in a forward mode over this time in order to interpret the natural variability of CO 2 . Our approach is based on the previous interpretation of carbon cycle variations during Termination I (Köhler et al., 2005a). In the absense of a process-based sediment module one main simplification of BICYCLE is that carbonate compensation is approximated by the temporally delayed restoration of deep ocean [CO 3 2− ]. Our results match the low frequency changes in CO 2 measured in the Vostok and the EPICA Dome C ice core for the last 650 kyr BP ( r 2 ≈0.75). During these transient simulations the carbon cycle reaches never a steady state due to the ongoing variability of the overall carbon budget caused by the time delayed response of the carbonate compensation to other processes. The average contributions of different processes to the rise in CO 2 during Terminations I to V and during earlier terminations are: the rise in Southern Ocean vertical mixing: 36/22 ppmv, the rise in ocean temperature: 26/11 ppmv, iron limitation of the marine biota in the Southern Ocean: 20/14 ppmv, carbonate compensation: 15/7 ppmv, the rise in North Atlantic deep water formation: 13/0 ppmv, the rise in gas exchange due to a decreasing sea ice cover: −8/−7 ppmv, sea level rise: −12/−4 ppmv, and rising terrestrial carbon storage: −13/−6 ppmv. According to our model the smaller interglacial CO 2 values in the pre-Vostok period prior to Termination V are mainly caused by smaller interglacial Southern Ocean SST and an Atlantic THC which stayed before MIS 11 (before 420 kyr BP) in its weaker glacial ... Article in Journal/Newspaper Antarc* Antarctic EPICA ice core North Atlantic Deep Water North Atlantic Sea ice Southern Ocean Directory of Open Access Journals: DOAJ Articles Antarctic Southern Ocean |
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. Köhler H. Fischer Simulating low frequency changes in atmospheric CO 2 during the last 740 000 years |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Atmospheric CO 2 measured in Antarctic ice cores shows a natural variability of 80 to 100 ppmv during the last four glacial cycles and variations of approximately 60 ppmv in the two cycles between 410 and 650 kyr BP. We here use various paleo-climatic records from the EPICA Dome C Antarctic ice core and from oceanic sediment cores covering the last 740 kyr to force the ocean/atmosphere/biosphere box model of the global carbon cycle BICYCLE in a forward mode over this time in order to interpret the natural variability of CO 2 . Our approach is based on the previous interpretation of carbon cycle variations during Termination I (Köhler et al., 2005a). In the absense of a process-based sediment module one main simplification of BICYCLE is that carbonate compensation is approximated by the temporally delayed restoration of deep ocean [CO 3 2− ]. Our results match the low frequency changes in CO 2 measured in the Vostok and the EPICA Dome C ice core for the last 650 kyr BP ( r 2 ≈0.75). During these transient simulations the carbon cycle reaches never a steady state due to the ongoing variability of the overall carbon budget caused by the time delayed response of the carbonate compensation to other processes. The average contributions of different processes to the rise in CO 2 during Terminations I to V and during earlier terminations are: the rise in Southern Ocean vertical mixing: 36/22 ppmv, the rise in ocean temperature: 26/11 ppmv, iron limitation of the marine biota in the Southern Ocean: 20/14 ppmv, carbonate compensation: 15/7 ppmv, the rise in North Atlantic deep water formation: 13/0 ppmv, the rise in gas exchange due to a decreasing sea ice cover: −8/−7 ppmv, sea level rise: −12/−4 ppmv, and rising terrestrial carbon storage: −13/−6 ppmv. According to our model the smaller interglacial CO 2 values in the pre-Vostok period prior to Termination V are mainly caused by smaller interglacial Southern Ocean SST and an Atlantic THC which stayed before MIS 11 (before 420 kyr BP) in its weaker glacial ... |
format |
Article in Journal/Newspaper |
author |
P. Köhler H. Fischer |
author_facet |
P. Köhler H. Fischer |
author_sort |
P. Köhler |
title |
Simulating low frequency changes in atmospheric CO 2 during the last 740 000 years |
title_short |
Simulating low frequency changes in atmospheric CO 2 during the last 740 000 years |
title_full |
Simulating low frequency changes in atmospheric CO 2 during the last 740 000 years |
title_fullStr |
Simulating low frequency changes in atmospheric CO 2 during the last 740 000 years |
title_full_unstemmed |
Simulating low frequency changes in atmospheric CO 2 during the last 740 000 years |
title_sort |
simulating low frequency changes in atmospheric co 2 during the last 740 000 years |
publisher |
Copernicus Publications |
publishDate |
2006 |
url |
https://doaj.org/article/306eab155c1a435fa721295569a51a2c |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic EPICA ice core North Atlantic Deep Water North Atlantic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic EPICA ice core North Atlantic Deep Water North Atlantic Sea ice Southern Ocean |
op_source |
Climate of the Past, Vol 2, Iss 2, Pp 57-78 (2006) |
op_relation |
http://www.clim-past.net/2/57/2006/cp-2-57-2006.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 https://doaj.org/article/306eab155c1a435fa721295569a51a2c |
_version_ |
1766274673537974272 |