Retrievals of chlorine chemistry kinetic parameters from Antarctic ClO microwave radiometer measurements
Key kinetic parameters governing the partitioning of chlorine species in the Antarctic polar stratosphere were retrieved from 28 days of chlorine monoxide (ClO) microwave radiometer measurements made during the late winter/early spring of 2005 at Scott Base (77.85° S, 166.75° E). During day-time the...
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München : European Geopyhsical Union
2011
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Online Access: | https://doi.org/10.34657/1211 https://oa.tib.eu/renate/handle/123456789/602 |
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ftleibnizopen:oai:oai.leibnizopen.de:kJNS04kBdbrxVwz6_iba 2023-10-01T03:51:49+02:00 Retrievals of chlorine chemistry kinetic parameters from Antarctic ClO microwave radiometer measurements Kremser, S. Schofield, R. Bodeker, G.E. Connor, B.J. Rex, M. Barret, J. Mooney, T. Salawitch, R.J. Canty, T. Frieler, K. Chipperfield, M.P. Langematz, U. Feng, W. 2011 application/pdf https://doi.org/10.34657/1211 https://oa.tib.eu/renate/handle/123456789/602 eng eng München : European Geopyhsical Union CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ Atmospheric Chemistry and Physics, Volume 11, Issue 11, Page 5183-5193 Air temperature atmospheric chemistry atmospheric pressure chlorine monoxide microwave radiometer ozone partitioning photochemistry photolysis reaction kinetics stratosphere 550 article Text 2011 ftleibnizopen https://doi.org/10.34657/1211 2023-09-03T23:38:27Z Key kinetic parameters governing the partitioning of chlorine species in the Antarctic polar stratosphere were retrieved from 28 days of chlorine monoxide (ClO) microwave radiometer measurements made during the late winter/early spring of 2005 at Scott Base (77.85° S, 166.75° E). During day-time the loss of the ClO dimer chlorine peroxide (ClOOCl) occurs mainly by photolysis. Some time after sunrise, a photochemical equilibrium is established and the ClO/ClOOCl partitioning is determined by the ratio of the photolysis frequency, J, and the dimer formation rate, kf. The values of J and kf from laboratory studies remain uncertain to a considerable extent, and as a complement to these ongoing studies, the goal of this work is to provide a constraint on that uncertainty based on observations of ClO profiles in the Antarctic. First an optimal estimation technique was used to derive J/kf ratios for a range of Keq values. The optimal estimation forward model was a photochemical box model that takes J, kf, and Keq as inputs, together with a priori profiles of activated chlorine (ClOx = ClO+2×ClOOCl), profiles of ozone, temperature, and pressure. JPL06 kinetics are used as a priori in the optimal estimation and for all other chemistry in the forward model. Using the more recent JPL09 kinetics results in insignificant differences in the retrieved value of J/kf. A complementary approach was used to derive the optimal kinetic parameters; the full parameter space of J, kf, Keq and ClOx was sampled to find the minimum in differences between measured and modelled ClO profiles. Furthermore, values of Keq up to 2.0 times larger than recommended by JPL06 were explored to test the sensitivity of the J/kf ratio to changes in Keq. The results show that the retrieved J/kf ratios bracket the range of 1.23 to 1.97 times the J/kf value recommended by JPL06 over the range of Keq values considered. The retrieved J/kf ratios lie in the lower half of the large uncertainty range of J/kf recommended by JPL06 and towards the upper portion of ... Article in Journal/Newspaper Antarc* Antarctic LeibnizOpen (The Leibniz Association) Antarctic Scott Base ENVELOPE(166.766,166.766,-77.849,-77.849) The Antarctic |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
Air temperature atmospheric chemistry atmospheric pressure chlorine monoxide microwave radiometer ozone partitioning photochemistry photolysis reaction kinetics stratosphere 550 |
spellingShingle |
Air temperature atmospheric chemistry atmospheric pressure chlorine monoxide microwave radiometer ozone partitioning photochemistry photolysis reaction kinetics stratosphere 550 Kremser, S. Schofield, R. Bodeker, G.E. Connor, B.J. Rex, M. Barret, J. Mooney, T. Salawitch, R.J. Canty, T. Frieler, K. Chipperfield, M.P. Langematz, U. Feng, W. Retrievals of chlorine chemistry kinetic parameters from Antarctic ClO microwave radiometer measurements |
topic_facet |
Air temperature atmospheric chemistry atmospheric pressure chlorine monoxide microwave radiometer ozone partitioning photochemistry photolysis reaction kinetics stratosphere 550 |
description |
Key kinetic parameters governing the partitioning of chlorine species in the Antarctic polar stratosphere were retrieved from 28 days of chlorine monoxide (ClO) microwave radiometer measurements made during the late winter/early spring of 2005 at Scott Base (77.85° S, 166.75° E). During day-time the loss of the ClO dimer chlorine peroxide (ClOOCl) occurs mainly by photolysis. Some time after sunrise, a photochemical equilibrium is established and the ClO/ClOOCl partitioning is determined by the ratio of the photolysis frequency, J, and the dimer formation rate, kf. The values of J and kf from laboratory studies remain uncertain to a considerable extent, and as a complement to these ongoing studies, the goal of this work is to provide a constraint on that uncertainty based on observations of ClO profiles in the Antarctic. First an optimal estimation technique was used to derive J/kf ratios for a range of Keq values. The optimal estimation forward model was a photochemical box model that takes J, kf, and Keq as inputs, together with a priori profiles of activated chlorine (ClOx = ClO+2×ClOOCl), profiles of ozone, temperature, and pressure. JPL06 kinetics are used as a priori in the optimal estimation and for all other chemistry in the forward model. Using the more recent JPL09 kinetics results in insignificant differences in the retrieved value of J/kf. A complementary approach was used to derive the optimal kinetic parameters; the full parameter space of J, kf, Keq and ClOx was sampled to find the minimum in differences between measured and modelled ClO profiles. Furthermore, values of Keq up to 2.0 times larger than recommended by JPL06 were explored to test the sensitivity of the J/kf ratio to changes in Keq. The results show that the retrieved J/kf ratios bracket the range of 1.23 to 1.97 times the J/kf value recommended by JPL06 over the range of Keq values considered. The retrieved J/kf ratios lie in the lower half of the large uncertainty range of J/kf recommended by JPL06 and towards the upper portion of ... |
format |
Article in Journal/Newspaper |
author |
Kremser, S. Schofield, R. Bodeker, G.E. Connor, B.J. Rex, M. Barret, J. Mooney, T. Salawitch, R.J. Canty, T. Frieler, K. Chipperfield, M.P. Langematz, U. Feng, W. |
author_facet |
Kremser, S. Schofield, R. Bodeker, G.E. Connor, B.J. Rex, M. Barret, J. Mooney, T. Salawitch, R.J. Canty, T. Frieler, K. Chipperfield, M.P. Langematz, U. Feng, W. |
author_sort |
Kremser, S. |
title |
Retrievals of chlorine chemistry kinetic parameters from Antarctic ClO microwave radiometer measurements |
title_short |
Retrievals of chlorine chemistry kinetic parameters from Antarctic ClO microwave radiometer measurements |
title_full |
Retrievals of chlorine chemistry kinetic parameters from Antarctic ClO microwave radiometer measurements |
title_fullStr |
Retrievals of chlorine chemistry kinetic parameters from Antarctic ClO microwave radiometer measurements |
title_full_unstemmed |
Retrievals of chlorine chemistry kinetic parameters from Antarctic ClO microwave radiometer measurements |
title_sort |
retrievals of chlorine chemistry kinetic parameters from antarctic clo microwave radiometer measurements |
publisher |
München : European Geopyhsical Union |
publishDate |
2011 |
url |
https://doi.org/10.34657/1211 https://oa.tib.eu/renate/handle/123456789/602 |
long_lat |
ENVELOPE(166.766,166.766,-77.849,-77.849) |
geographic |
Antarctic Scott Base The Antarctic |
geographic_facet |
Antarctic Scott Base The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Atmospheric Chemistry and Physics, Volume 11, Issue 11, Page 5183-5193 |
op_rights |
CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.34657/1211 |
_version_ |
1778517111267655680 |