Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød
One of the most abrupt and yet unexplained past rises in atmospheric CO2 (10 ppmv in two centuries in the EPICA Dome C [EDC] ice core) occurred in quasi-synchrony with abrupt northern hemispheric warming into the Bølling/Allerød, about 14.6 ka ago. In Köhler et al. (2014) we used a U/Th-dated record...
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ftawi:oai:epic.awi.de:41142 2024-09-15T17:47:55+00:00 Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød Köhler, Peter Knorr, Gregor Bard, Edouard 2016-06-21 application/pdf https://epic.awi.de/id/eprint/41142/ https://epic.awi.de/id/eprint/41142/1/icop2016_ba14c.pdf https://hdl.handle.net/10013/epic.48088 https://hdl.handle.net/10013/epic.48088.d001 unknown https://epic.awi.de/id/eprint/41142/1/icop2016_ba14c.pdf https://hdl.handle.net/10013/epic.48088.d001 Köhler, P. orcid:0000-0003-0904-8484 , Knorr, G. orcid:0000-0002-8317-5046 and Bard, E. (2016) Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød , XI. International Conference on Permafrost (ICOP2016), Potsdam, Germany, 20 June 2016 - 25 June 2016 . hdl:10013/epic.48088 EPIC3XI. International Conference on Permafrost (ICOP2016), Potsdam, Germany, 2016-06-20-2016-06-25 Conference notRev 2016 ftawi 2024-06-24T04:14:20Z One of the most abrupt and yet unexplained past rises in atmospheric CO2 (10 ppmv in two centuries in the EPICA Dome C [EDC] ice core) occurred in quasi-synchrony with abrupt northern hemispheric warming into the Bølling/Allerød, about 14.6 ka ago. In Köhler et al. (2014) we used a U/Th-dated record of atmospheric Δ14C from Tahiti corals to provide an independent and precise age control for this CO2 rise. We also used model simulations to show that the release of old (nearly 14C-free) carbon can explain these changes in CO2 and Δ14C. The Δ14C record provides an independent constraint on the amount of carbon released (125 PgC). We suggest, in line with observations of atmospheric CH4 and terrigenous biomarkers, that thawing permafrost in high northern latitudes could have been the source of carbon, possibly with contribution from flooding of the Siberian continental shelf during meltwater pulse 1A. Our findings highlight the potential of the permafrost carbon reservoir to modulate abrupt climate changes via greenhouse-gas feedbacks. These calculations and conclusions were challenged by the new CO2 data (Marcott et al. 2014) from the West Antarctic Ice Sheet Divide Ice Core (WDC), which have a higher temporal resolution. We therefore revised our carbon release experiments in order to meet these new WDC CO2 data. We furthermore used a new age distribution during gas enclosure in ice which includes the most recent understanding of firn densification. We then can align EDC and WDC CO2 data and propose a peak amplitude in atmospheric CO2 of about 15 ppmv around 14.6 ka BP corresponding to a C pulse of 85 PgC released in 200 years (0.425 PgC per year). This is 68% of the initial suggested strength of the C pulse of 125 PgC, that then led to a peak amplitude in true atmospheric CO2 of 22 ppmv. CO2 data from other ice cores suggest that the amplitude in atmospheric CO2 was in-between both these scenarios. The revised scenario proposes a carbon release that is still large enough to explain the atmospheric Δ14C anomaly of ... Conference Object Antarc* Antarctic EPICA Ice ice core Ice Sheet permafrost Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
institution |
Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
One of the most abrupt and yet unexplained past rises in atmospheric CO2 (10 ppmv in two centuries in the EPICA Dome C [EDC] ice core) occurred in quasi-synchrony with abrupt northern hemispheric warming into the Bølling/Allerød, about 14.6 ka ago. In Köhler et al. (2014) we used a U/Th-dated record of atmospheric Δ14C from Tahiti corals to provide an independent and precise age control for this CO2 rise. We also used model simulations to show that the release of old (nearly 14C-free) carbon can explain these changes in CO2 and Δ14C. The Δ14C record provides an independent constraint on the amount of carbon released (125 PgC). We suggest, in line with observations of atmospheric CH4 and terrigenous biomarkers, that thawing permafrost in high northern latitudes could have been the source of carbon, possibly with contribution from flooding of the Siberian continental shelf during meltwater pulse 1A. Our findings highlight the potential of the permafrost carbon reservoir to modulate abrupt climate changes via greenhouse-gas feedbacks. These calculations and conclusions were challenged by the new CO2 data (Marcott et al. 2014) from the West Antarctic Ice Sheet Divide Ice Core (WDC), which have a higher temporal resolution. We therefore revised our carbon release experiments in order to meet these new WDC CO2 data. We furthermore used a new age distribution during gas enclosure in ice which includes the most recent understanding of firn densification. We then can align EDC and WDC CO2 data and propose a peak amplitude in atmospheric CO2 of about 15 ppmv around 14.6 ka BP corresponding to a C pulse of 85 PgC released in 200 years (0.425 PgC per year). This is 68% of the initial suggested strength of the C pulse of 125 PgC, that then led to a peak amplitude in true atmospheric CO2 of 22 ppmv. CO2 data from other ice cores suggest that the amplitude in atmospheric CO2 was in-between both these scenarios. The revised scenario proposes a carbon release that is still large enough to explain the atmospheric Δ14C anomaly of ... |
format |
Conference Object |
author |
Köhler, Peter Knorr, Gregor Bard, Edouard |
spellingShingle |
Köhler, Peter Knorr, Gregor Bard, Edouard Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød |
author_facet |
Köhler, Peter Knorr, Gregor Bard, Edouard |
author_sort |
Köhler, Peter |
title |
Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød |
title_short |
Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød |
title_full |
Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød |
title_fullStr |
Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød |
title_full_unstemmed |
Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød |
title_sort |
permafrost thawing as a possible source of abrupt carbon release at the onset of the bølling/allerød |
publishDate |
2016 |
url |
https://epic.awi.de/id/eprint/41142/ https://epic.awi.de/id/eprint/41142/1/icop2016_ba14c.pdf https://hdl.handle.net/10013/epic.48088 https://hdl.handle.net/10013/epic.48088.d001 |
genre |
Antarc* Antarctic EPICA Ice ice core Ice Sheet permafrost |
genre_facet |
Antarc* Antarctic EPICA Ice ice core Ice Sheet permafrost |
op_source |
EPIC3XI. International Conference on Permafrost (ICOP2016), Potsdam, Germany, 2016-06-20-2016-06-25 |
op_relation |
https://epic.awi.de/id/eprint/41142/1/icop2016_ba14c.pdf https://hdl.handle.net/10013/epic.48088.d001 Köhler, P. orcid:0000-0003-0904-8484 , Knorr, G. orcid:0000-0002-8317-5046 and Bard, E. (2016) Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød , XI. International Conference on Permafrost (ICOP2016), Potsdam, Germany, 20 June 2016 - 25 June 2016 . hdl:10013/epic.48088 |
_version_ |
1810497631966724096 |