Constraining N2O emissions since 1940 using firn air isotope measurements in both hemispheres
N2O is currently the third most important anthropogenic greenhouse gas in terms of radiative forcing and its atmospheric mole fraction is rising steadily. To quantify the growth rate and its causes over the past decades, we performed a multi-site reconstruction of the atmospheric N2O mole fraction a...
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ftunivutrecht:oai:dspace.library.uu.nl:1874/348959 2023-07-23T04:15:47+02:00 Constraining N2O emissions since 1940 using firn air isotope measurements in both hemispheres Prokopiou, Markella Martinerie, Patricia Sapart, Célia J. Witrant, Emmanuel Monteil, Guillaume Ishijima, Kentaro Bernard, Sophie Kaiser, Jan Levin, Ingeborg Blunier, Thomas Etheridge, David Dlugokencky, Ed Van De Wal, Roderik S W Röckmann, Thomas Sub Atmospheric physics and chemistry Marine and Atmospheric Research 2017-04-05 image/pdf https://dspace.library.uu.nl/handle/1874/348959 en eng 1680-7316 https://dspace.library.uu.nl/handle/1874/348959 info:eu-repo/semantics/OpenAccess Atmospheric Science Article 2017 ftunivutrecht 2023-07-02T02:05:18Z N2O is currently the third most important anthropogenic greenhouse gas in terms of radiative forcing and its atmospheric mole fraction is rising steadily. To quantify the growth rate and its causes over the past decades, we performed a multi-site reconstruction of the atmospheric N2O mole fraction and isotopic composition using new and previously published firn air data collected from Greenland and Antarctica in combination with a firn diffusion and densification model. The multi-site reconstruction showed that while the global mean N2O mole fraction increased from (290±1)nmolmol-1 in 1940 to (322±1)nmolmol-1 in 2008, the isotopic composition of atmospheric N2O decreased by (-2.2±0.2)% for δ15Nav, (-1.0±0.3)% for δ18O, (-1.3±0.6)% for δ15Nα, and (-2.8±0.6)% for δ15Nβ over the same period. The detailed temporal evolution of the mole fraction and isotopic composition derived from the firn air model was then used in a two-box atmospheric model (comprising a stratospheric box and a tropospheric box) to infer changes in the isotopic source signature over time. The precise value of the source strength depends on the choice of the N2O lifetime, which we choose to fix at 123 years. The average isotopic composition over the investigated period is δ15Nav Combining double low line (-7.6±0.8)% (vs. air-N2), δ18O Combining double low line (32.2±0.2)% (vs. Vienna Standard Mean Ocean Water-VSMOW) for δ18O, δ15Nα Combining double low line (-3.0±1.9)% and δ15Nβ Combining double low line (-11.7±2.3)%. δ15Nav, and δ15Nβ show some temporal variability, while for the other signatures the error bars of the reconstruction are too large to retrieve reliable temporal changes. Possible processes that may explain trends in 15N are discussed. The 15N site preference (Combining double low line δ15Nα-δ15Nβ) provides evidence of a shift in emissions from denitrification to nitrification, although the uncertainty envelopes are large. Article in Journal/Newspaper Antarc* Antarctica Greenland Utrecht University Repository Greenland |
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Open Polar |
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Utrecht University Repository |
op_collection_id |
ftunivutrecht |
language |
English |
topic |
Atmospheric Science |
spellingShingle |
Atmospheric Science Prokopiou, Markella Martinerie, Patricia Sapart, Célia J. Witrant, Emmanuel Monteil, Guillaume Ishijima, Kentaro Bernard, Sophie Kaiser, Jan Levin, Ingeborg Blunier, Thomas Etheridge, David Dlugokencky, Ed Van De Wal, Roderik S W Röckmann, Thomas Constraining N2O emissions since 1940 using firn air isotope measurements in both hemispheres |
topic_facet |
Atmospheric Science |
description |
N2O is currently the third most important anthropogenic greenhouse gas in terms of radiative forcing and its atmospheric mole fraction is rising steadily. To quantify the growth rate and its causes over the past decades, we performed a multi-site reconstruction of the atmospheric N2O mole fraction and isotopic composition using new and previously published firn air data collected from Greenland and Antarctica in combination with a firn diffusion and densification model. The multi-site reconstruction showed that while the global mean N2O mole fraction increased from (290±1)nmolmol-1 in 1940 to (322±1)nmolmol-1 in 2008, the isotopic composition of atmospheric N2O decreased by (-2.2±0.2)% for δ15Nav, (-1.0±0.3)% for δ18O, (-1.3±0.6)% for δ15Nα, and (-2.8±0.6)% for δ15Nβ over the same period. The detailed temporal evolution of the mole fraction and isotopic composition derived from the firn air model was then used in a two-box atmospheric model (comprising a stratospheric box and a tropospheric box) to infer changes in the isotopic source signature over time. The precise value of the source strength depends on the choice of the N2O lifetime, which we choose to fix at 123 years. The average isotopic composition over the investigated period is δ15Nav Combining double low line (-7.6±0.8)% (vs. air-N2), δ18O Combining double low line (32.2±0.2)% (vs. Vienna Standard Mean Ocean Water-VSMOW) for δ18O, δ15Nα Combining double low line (-3.0±1.9)% and δ15Nβ Combining double low line (-11.7±2.3)%. δ15Nav, and δ15Nβ show some temporal variability, while for the other signatures the error bars of the reconstruction are too large to retrieve reliable temporal changes. Possible processes that may explain trends in 15N are discussed. The 15N site preference (Combining double low line δ15Nα-δ15Nβ) provides evidence of a shift in emissions from denitrification to nitrification, although the uncertainty envelopes are large. |
author2 |
Sub Atmospheric physics and chemistry Marine and Atmospheric Research |
format |
Article in Journal/Newspaper |
author |
Prokopiou, Markella Martinerie, Patricia Sapart, Célia J. Witrant, Emmanuel Monteil, Guillaume Ishijima, Kentaro Bernard, Sophie Kaiser, Jan Levin, Ingeborg Blunier, Thomas Etheridge, David Dlugokencky, Ed Van De Wal, Roderik S W Röckmann, Thomas |
author_facet |
Prokopiou, Markella Martinerie, Patricia Sapart, Célia J. Witrant, Emmanuel Monteil, Guillaume Ishijima, Kentaro Bernard, Sophie Kaiser, Jan Levin, Ingeborg Blunier, Thomas Etheridge, David Dlugokencky, Ed Van De Wal, Roderik S W Röckmann, Thomas |
author_sort |
Prokopiou, Markella |
title |
Constraining N2O emissions since 1940 using firn air isotope measurements in both hemispheres |
title_short |
Constraining N2O emissions since 1940 using firn air isotope measurements in both hemispheres |
title_full |
Constraining N2O emissions since 1940 using firn air isotope measurements in both hemispheres |
title_fullStr |
Constraining N2O emissions since 1940 using firn air isotope measurements in both hemispheres |
title_full_unstemmed |
Constraining N2O emissions since 1940 using firn air isotope measurements in both hemispheres |
title_sort |
constraining n2o emissions since 1940 using firn air isotope measurements in both hemispheres |
publishDate |
2017 |
url |
https://dspace.library.uu.nl/handle/1874/348959 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Antarc* Antarctica Greenland |
genre_facet |
Antarc* Antarctica Greenland |
op_relation |
1680-7316 https://dspace.library.uu.nl/handle/1874/348959 |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1772176812962480128 |