Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble
During long-range transport, many distinct processes – including photochemistry, deposition, emissions and mixing – contribute to the transformation of air mass composition. Partitioning the effects of different processes can be useful when considering the sensitivity of chemical transformation to,...
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ftunivreading:oai:centaur.reading.ac.uk:32706 2024-02-11T10:06:45+01:00 Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble Cain, M. Methven, J. Highwood, E.J. 2012-01-27 https://centaur.reading.ac.uk/32706/ unknown Copernicus for the European Geosciences Union Cain, M., Methven, J. <https://centaur.reading.ac.uk/view/creators/90000334.html> orcid:0000-0002-7636-6872 and Highwood, E.J. <https://centaur.reading.ac.uk/view/creators/90000039.html> (2012) Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble. Atmospheric Chemistry and Physics, 12 (15). pp. 7015-7039. ISSN 1680-7316 doi: https://doi.org/10.5194/acp-12-7015-2012 <https://doi.org/10.5194/acp-12-7015-2012> Article PeerReviewed 2012 ftunivreading https://doi.org/10.5194/acp-12-7015-2012 2024-01-25T23:57:20Z During long-range transport, many distinct processes – including photochemistry, deposition, emissions and mixing – contribute to the transformation of air mass composition. Partitioning the effects of different processes can be useful when considering the sensitivity of chemical transformation to, for example, a changing environment or anthropogenic influence. However, transformation is not observed directly, since mixing ratios are measured, and models must be used to relate changes to processes. Here, four cases from the ITCT-Lagrangian 2004 experiment are studied. In each case, aircraft intercepted a distinct air mass several times during transport over the North Atlantic, providing a unique dataset and quantifying the net changes in composition from all processes. A new framework is presented to deconstruct the change in O3 mixing ratio (Δ O3) into its component processes, which were not measured directly, taking into account the uncertainty in measurements, initial air mass variability and its time evolution. The results show that the net chemical processing (Δ O3chem) over the whole simulation is greater than net physical processing (Δ O3phys) in all cases. This is in part explained by cancellation effects associated with mixing. In contrast, each case is in a regime of either net photochemical destruction (lower tropospheric transport) or production (an upper tropospheric biomass burning case). However, physical processes influence O3 indirectly through addition or removal of precursor gases, so that changes to physical parameters in a model can have a larger effect on Δ O3chem than Δ O3phys. Despite its smaller magnitude, the physical processing distinguishes the lower tropospheric export cases, since the net photochemical O3 change is −5 ppbv per day in all three cases. Processing is quantified using a Lagrangian photochemical model with a novel method for simulating mixing through an ensemble of trajectories and a background profile that evolves with them. The model is able to simulate the magnitude ... Article in Journal/Newspaper North Atlantic CentAUR: Central Archive at the University of Reading Atmospheric Chemistry and Physics 12 15 7015 7039 |
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CentAUR: Central Archive at the University of Reading |
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description |
During long-range transport, many distinct processes – including photochemistry, deposition, emissions and mixing – contribute to the transformation of air mass composition. Partitioning the effects of different processes can be useful when considering the sensitivity of chemical transformation to, for example, a changing environment or anthropogenic influence. However, transformation is not observed directly, since mixing ratios are measured, and models must be used to relate changes to processes. Here, four cases from the ITCT-Lagrangian 2004 experiment are studied. In each case, aircraft intercepted a distinct air mass several times during transport over the North Atlantic, providing a unique dataset and quantifying the net changes in composition from all processes. A new framework is presented to deconstruct the change in O3 mixing ratio (Δ O3) into its component processes, which were not measured directly, taking into account the uncertainty in measurements, initial air mass variability and its time evolution. The results show that the net chemical processing (Δ O3chem) over the whole simulation is greater than net physical processing (Δ O3phys) in all cases. This is in part explained by cancellation effects associated with mixing. In contrast, each case is in a regime of either net photochemical destruction (lower tropospheric transport) or production (an upper tropospheric biomass burning case). However, physical processes influence O3 indirectly through addition or removal of precursor gases, so that changes to physical parameters in a model can have a larger effect on Δ O3chem than Δ O3phys. Despite its smaller magnitude, the physical processing distinguishes the lower tropospheric export cases, since the net photochemical O3 change is −5 ppbv per day in all three cases. Processing is quantified using a Lagrangian photochemical model with a novel method for simulating mixing through an ensemble of trajectories and a background profile that evolves with them. The model is able to simulate the magnitude ... |
format |
Article in Journal/Newspaper |
author |
Cain, M. Methven, J. Highwood, E.J. |
spellingShingle |
Cain, M. Methven, J. Highwood, E.J. Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble |
author_facet |
Cain, M. Methven, J. Highwood, E.J. |
author_sort |
Cain, M. |
title |
Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble |
title_short |
Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble |
title_full |
Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble |
title_fullStr |
Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble |
title_full_unstemmed |
Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble |
title_sort |
quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble |
publisher |
Copernicus for the European Geosciences Union |
publishDate |
2012 |
url |
https://centaur.reading.ac.uk/32706/ |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Cain, M., Methven, J. <https://centaur.reading.ac.uk/view/creators/90000334.html> orcid:0000-0002-7636-6872 and Highwood, E.J. <https://centaur.reading.ac.uk/view/creators/90000039.html> (2012) Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble. Atmospheric Chemistry and Physics, 12 (15). pp. 7015-7039. ISSN 1680-7316 doi: https://doi.org/10.5194/acp-12-7015-2012 <https://doi.org/10.5194/acp-12-7015-2012> |
op_doi |
https://doi.org/10.5194/acp-12-7015-2012 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
12 |
container_issue |
15 |
container_start_page |
7015 |
op_container_end_page |
7039 |
_version_ |
1790604654674968576 |