Marine N2O emissions during a Younger Dryas-like event: the role of meridional overturning, tropical thermocline ventilation, and biological productivity
Past variations in atmospheric nitrous oxide (N _2 O) allow important insight into abrupt climate events. Here, we investigate marine N _2 O emissions by forcing the Bern3D Earth System Model of Intermediate Complexity with freshwater into the North Atlantic. The model simulates a decrease in marine...
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ftdoajarticles:oai:doaj.org/article:c7e87b24aa87460584fdf24476e6f3fd 2023-09-05T13:21:28+02:00 Marine N2O emissions during a Younger Dryas-like event: the role of meridional overturning, tropical thermocline ventilation, and biological productivity Fortunat Joos Gianna Battaglia Hubertus Fischer Aurich Jeltsch-Thömmes Jochen Schmitt 2019-01-01T00:00:00Z https://doi.org/10.1088/1748-9326/ab2353 https://doaj.org/article/c7e87b24aa87460584fdf24476e6f3fd EN eng IOP Publishing https://doi.org/10.1088/1748-9326/ab2353 https://doaj.org/toc/1748-9326 doi:10.1088/1748-9326/ab2353 1748-9326 https://doaj.org/article/c7e87b24aa87460584fdf24476e6f3fd Environmental Research Letters, Vol 14, Iss 7, p 075007 (2019) nitrous oxide Younger Dryas marine nitrous oxide emissions freshwater hosing experiment Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 article 2019 ftdoajarticles https://doi.org/10.1088/1748-9326/ab2353 2023-08-13T00:37:28Z Past variations in atmospheric nitrous oxide (N _2 O) allow important insight into abrupt climate events. Here, we investigate marine N _2 O emissions by forcing the Bern3D Earth System Model of Intermediate Complexity with freshwater into the North Atlantic. The model simulates a decrease in marine N _2 O emissions of about 0.8 TgN yr ^−1 followed by a recovery, in reasonable agreement regarding timing and magnitude with isotope-based reconstructions of marine emissions for the Younger Dryas Northern Hemisphere cold event. In the model the freshwater forcing causes a transient near-collapse of the Atlantic Meridional Overturning Circulation (AMOC) leading to a fast adjustment in thermocline ventilation and an increase in O _2 in tropical eastern boundary systems and in the tropical Indian Ocean. In turn, net production by nitrification and denitrification and N _2 O emissions decrease in these regions. The decrease in organic matter export, mainly in the North Atlantic where ventilation and nutrient supply is suppressed, explains the remaining emission reduction. Modeled global marine N _2 O production and emission changes are delayed, initially by up to 300 years, relative to the AMOC decrease, but by less than 50 years at peak decline. The N _2 O perturbation is recovering only slowly and the lag between the recovery in AMOC and the recovery in N _2 O emissions and atmospheric concentrations exceeds 400 years. Thus, our results suggest a century-scale lag between ocean circulation and marine N _2 O emissions, and a tight coupling between changes in AMOC and tropical thermocline ventilation. Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Indian Environmental Research Letters 14 7 075007 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
nitrous oxide Younger Dryas marine nitrous oxide emissions freshwater hosing experiment Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 |
spellingShingle |
nitrous oxide Younger Dryas marine nitrous oxide emissions freshwater hosing experiment Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 Fortunat Joos Gianna Battaglia Hubertus Fischer Aurich Jeltsch-Thömmes Jochen Schmitt Marine N2O emissions during a Younger Dryas-like event: the role of meridional overturning, tropical thermocline ventilation, and biological productivity |
topic_facet |
nitrous oxide Younger Dryas marine nitrous oxide emissions freshwater hosing experiment Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 |
description |
Past variations in atmospheric nitrous oxide (N _2 O) allow important insight into abrupt climate events. Here, we investigate marine N _2 O emissions by forcing the Bern3D Earth System Model of Intermediate Complexity with freshwater into the North Atlantic. The model simulates a decrease in marine N _2 O emissions of about 0.8 TgN yr ^−1 followed by a recovery, in reasonable agreement regarding timing and magnitude with isotope-based reconstructions of marine emissions for the Younger Dryas Northern Hemisphere cold event. In the model the freshwater forcing causes a transient near-collapse of the Atlantic Meridional Overturning Circulation (AMOC) leading to a fast adjustment in thermocline ventilation and an increase in O _2 in tropical eastern boundary systems and in the tropical Indian Ocean. In turn, net production by nitrification and denitrification and N _2 O emissions decrease in these regions. The decrease in organic matter export, mainly in the North Atlantic where ventilation and nutrient supply is suppressed, explains the remaining emission reduction. Modeled global marine N _2 O production and emission changes are delayed, initially by up to 300 years, relative to the AMOC decrease, but by less than 50 years at peak decline. The N _2 O perturbation is recovering only slowly and the lag between the recovery in AMOC and the recovery in N _2 O emissions and atmospheric concentrations exceeds 400 years. Thus, our results suggest a century-scale lag between ocean circulation and marine N _2 O emissions, and a tight coupling between changes in AMOC and tropical thermocline ventilation. |
format |
Article in Journal/Newspaper |
author |
Fortunat Joos Gianna Battaglia Hubertus Fischer Aurich Jeltsch-Thömmes Jochen Schmitt |
author_facet |
Fortunat Joos Gianna Battaglia Hubertus Fischer Aurich Jeltsch-Thömmes Jochen Schmitt |
author_sort |
Fortunat Joos |
title |
Marine N2O emissions during a Younger Dryas-like event: the role of meridional overturning, tropical thermocline ventilation, and biological productivity |
title_short |
Marine N2O emissions during a Younger Dryas-like event: the role of meridional overturning, tropical thermocline ventilation, and biological productivity |
title_full |
Marine N2O emissions during a Younger Dryas-like event: the role of meridional overturning, tropical thermocline ventilation, and biological productivity |
title_fullStr |
Marine N2O emissions during a Younger Dryas-like event: the role of meridional overturning, tropical thermocline ventilation, and biological productivity |
title_full_unstemmed |
Marine N2O emissions during a Younger Dryas-like event: the role of meridional overturning, tropical thermocline ventilation, and biological productivity |
title_sort |
marine n2o emissions during a younger dryas-like event: the role of meridional overturning, tropical thermocline ventilation, and biological productivity |
publisher |
IOP Publishing |
publishDate |
2019 |
url |
https://doi.org/10.1088/1748-9326/ab2353 https://doaj.org/article/c7e87b24aa87460584fdf24476e6f3fd |
geographic |
Indian |
geographic_facet |
Indian |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Environmental Research Letters, Vol 14, Iss 7, p 075007 (2019) |
op_relation |
https://doi.org/10.1088/1748-9326/ab2353 https://doaj.org/toc/1748-9326 doi:10.1088/1748-9326/ab2353 1748-9326 https://doaj.org/article/c7e87b24aa87460584fdf24476e6f3fd |
op_doi |
https://doi.org/10.1088/1748-9326/ab2353 |
container_title |
Environmental Research Letters |
container_volume |
14 |
container_issue |
7 |
container_start_page |
075007 |
_version_ |
1776202081285177344 |