Measurements of OH and RO 2 radicals at Dome C, East Antarctica
Concentrations of OH radicals and the sum of peroxy radicals, RO 2 , were measured in the boundary layer for the first time on the East Antarctic Plateau at the Concordia Station (Dome C, 75.10° S, 123.31° E) during the austral summer 2011/2012. The median concentrations of OH and RO 2 radicals were...
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ftdoajarticles:oai:doaj.org/article:b4b447fbc22347769702784fd4acbf01 2023-05-15T13:54:00+02:00 Measurements of OH and RO 2 radicals at Dome C, East Antarctica A. Kukui M. Legrand S. Preunkert M. M. Frey R. Loisil J. Gil Roca B. Jourdain M. D. King J. L. France G. Ancellet 2014-11-01T00:00:00Z https://doi.org/10.5194/acp-14-12373-2014 https://doaj.org/article/b4b447fbc22347769702784fd4acbf01 EN eng Copernicus Publications http://www.atmos-chem-phys.net/14/12373/2014/acp-14-12373-2014.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 doi:10.5194/acp-14-12373-2014 https://doaj.org/article/b4b447fbc22347769702784fd4acbf01 Atmospheric Chemistry and Physics, Vol 14, Iss 22, Pp 12373-12392 (2014) Physics QC1-999 Chemistry QD1-999 article 2014 ftdoajarticles https://doi.org/10.5194/acp-14-12373-2014 2022-12-31T14:41:42Z Concentrations of OH radicals and the sum of peroxy radicals, RO 2 , were measured in the boundary layer for the first time on the East Antarctic Plateau at the Concordia Station (Dome C, 75.10° S, 123.31° E) during the austral summer 2011/2012. The median concentrations of OH and RO 2 radicals were 3.1 × 10 6 molecule cm −3 and 9.9 × 10 6 molecule cm −3 , respectively. These values are comparable to those observed at the South Pole, confirming that the elevated oxidative capacity of the Antarctic atmospheric boundary layer found at the South Pole is not restricted to the South Pole but common over the high Antarctic plateau. At Concordia, the concentration of radicals showed distinct diurnal profiles with the median maximum of 5.2 × 10 6 molecule cm −3 at 11:00 and the median minimum of 1.1 × 10 6 molecule cm −3 at 01:00 for OH radicals and 1.7 × 10 8 molecule cm −3 and 2.5 × 10 7 molecule cm −3 for RO 2 radicals at 13:00 and 23:00, respectively (all times are local times). Concurrent measurements of O 3 , HONO, NO, NO 2 , HCHO and H 2 O 2 demonstrated that the major primary source of OH and RO 2 radicals at Dome C was the photolysis of HONO, HCHO and H 2 O 2 , with the photolysis of HONO contributing ~75% of total primary radical production. However, photochemical modelling with accounting for all these radical sources overestimates the concentrations of OH and RO 2 radicals by a factor of 2 compared to field observations. Neglecting the net OH production from HONO in the photochemical modelling results in an underestimation of the concentrations of OH and RO 2 radicals by a factor of 2. To explain the observations of radicals in this case an additional source of OH equivalent to about (25–35)% of measured photolysis of HONO is required. Even with a factor of 5 reduction in the concentrations of HONO, the photolysis of HONO represents the major primary radical source at Dome C. To account for a possibility of an overestimation of NO 2 observed at Dome C the calculations were also performed with NO 2 ... Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica South pole South pole Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic East Antarctica Austral South Pole Concordia Station ENVELOPE(123.333,123.333,-75.100,-75.100) Atmospheric Chemistry and Physics 14 22 12373 12392 |
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Directory of Open Access Journals: DOAJ Articles |
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topic |
Physics QC1-999 Chemistry QD1-999 |
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Physics QC1-999 Chemistry QD1-999 A. Kukui M. Legrand S. Preunkert M. M. Frey R. Loisil J. Gil Roca B. Jourdain M. D. King J. L. France G. Ancellet Measurements of OH and RO 2 radicals at Dome C, East Antarctica |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
Concentrations of OH radicals and the sum of peroxy radicals, RO 2 , were measured in the boundary layer for the first time on the East Antarctic Plateau at the Concordia Station (Dome C, 75.10° S, 123.31° E) during the austral summer 2011/2012. The median concentrations of OH and RO 2 radicals were 3.1 × 10 6 molecule cm −3 and 9.9 × 10 6 molecule cm −3 , respectively. These values are comparable to those observed at the South Pole, confirming that the elevated oxidative capacity of the Antarctic atmospheric boundary layer found at the South Pole is not restricted to the South Pole but common over the high Antarctic plateau. At Concordia, the concentration of radicals showed distinct diurnal profiles with the median maximum of 5.2 × 10 6 molecule cm −3 at 11:00 and the median minimum of 1.1 × 10 6 molecule cm −3 at 01:00 for OH radicals and 1.7 × 10 8 molecule cm −3 and 2.5 × 10 7 molecule cm −3 for RO 2 radicals at 13:00 and 23:00, respectively (all times are local times). Concurrent measurements of O 3 , HONO, NO, NO 2 , HCHO and H 2 O 2 demonstrated that the major primary source of OH and RO 2 radicals at Dome C was the photolysis of HONO, HCHO and H 2 O 2 , with the photolysis of HONO contributing ~75% of total primary radical production. However, photochemical modelling with accounting for all these radical sources overestimates the concentrations of OH and RO 2 radicals by a factor of 2 compared to field observations. Neglecting the net OH production from HONO in the photochemical modelling results in an underestimation of the concentrations of OH and RO 2 radicals by a factor of 2. To explain the observations of radicals in this case an additional source of OH equivalent to about (25–35)% of measured photolysis of HONO is required. Even with a factor of 5 reduction in the concentrations of HONO, the photolysis of HONO represents the major primary radical source at Dome C. To account for a possibility of an overestimation of NO 2 observed at Dome C the calculations were also performed with NO 2 ... |
format |
Article in Journal/Newspaper |
author |
A. Kukui M. Legrand S. Preunkert M. M. Frey R. Loisil J. Gil Roca B. Jourdain M. D. King J. L. France G. Ancellet |
author_facet |
A. Kukui M. Legrand S. Preunkert M. M. Frey R. Loisil J. Gil Roca B. Jourdain M. D. King J. L. France G. Ancellet |
author_sort |
A. Kukui |
title |
Measurements of OH and RO 2 radicals at Dome C, East Antarctica |
title_short |
Measurements of OH and RO 2 radicals at Dome C, East Antarctica |
title_full |
Measurements of OH and RO 2 radicals at Dome C, East Antarctica |
title_fullStr |
Measurements of OH and RO 2 radicals at Dome C, East Antarctica |
title_full_unstemmed |
Measurements of OH and RO 2 radicals at Dome C, East Antarctica |
title_sort |
measurements of oh and ro 2 radicals at dome c, east antarctica |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/acp-14-12373-2014 https://doaj.org/article/b4b447fbc22347769702784fd4acbf01 |
long_lat |
ENVELOPE(123.333,123.333,-75.100,-75.100) |
geographic |
Antarctic The Antarctic East Antarctica Austral South Pole Concordia Station |
geographic_facet |
Antarctic The Antarctic East Antarctica Austral South Pole Concordia Station |
genre |
Antarc* Antarctic Antarctica East Antarctica South pole South pole |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica South pole South pole |
op_source |
Atmospheric Chemistry and Physics, Vol 14, Iss 22, Pp 12373-12392 (2014) |
op_relation |
http://www.atmos-chem-phys.net/14/12373/2014/acp-14-12373-2014.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 doi:10.5194/acp-14-12373-2014 https://doaj.org/article/b4b447fbc22347769702784fd4acbf01 |
op_doi |
https://doi.org/10.5194/acp-14-12373-2014 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
14 |
container_issue |
22 |
container_start_page |
12373 |
op_container_end_page |
12392 |
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1766259505108090880 |