| Title | Observations of OH and HO2 radicals in coastal Antarctica |
| Author | Bloss, W.J.; Lee, J.D.; Heard, D.E.; Salmon, R.A.; Bauguitte, S.J.B.; Roscoe, H.K.; Jones, A.E. |
| Author Affil | Bloss, W.J., University of Leeds, School of Chemistry, Leeds, United Kingdom. Other: British Antarctic Survey, United Kingdom; University of Birmingham, United Kingdom; University of York, United Kingdom |
| Source | Atmospheric Chemistry and Physics, 7(16), p.4171-4185, . Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316 |
| Publication Date | 2007 |
| Notes | In English. Part of a special issue, Chemistry of the Antarctic boundary layer and the interface with snow (CHABLIS), edited by Jones, A, Lee, J. and Sturges, B., http://www.atmos-chem- phys.net/special_issue79.html; discussion at: http://www.atmos-chem-phys- discuss.net/7/2893/2007/acpd-7-2893- 2007.html. 56 refs. Ant. Acc. No: 84136. GeoRef Acc. No: 284787 |
| Index Terms | hydrocarbons; lasers; measurement; meteorology; ozone; polar regions; polar atmospheres; snow; water; Antarctica; polar regions; aldehydes; aliphatic hydrocarbons; alkanes; atmosphere; bromides; carbon monoxide; coastal environment; environmental analysis; fluorescence; glacial environment; halides; Halley Research Station; halogens; laser methods; methane; nitrous oxide; organic compounds; oxidation; photochemistry; photolysis; sinks |
| Abstract | OH and HO2 radical concentrations have been measured in the boundary layer of coastal Antarctica for a six-week period during the austral summer of 2005. The measurements were performed at the British Antarctic Survey's Halley Research Station (75°35'S, 26°19'W), using the technique of on- resonance laser-induced fluorescence to detect OH, with HO2 measured following chemical conversion through addition of NO. The mean radical levels were 3.9×105 molecule cm-3 for OH, and 0.76 ppt for HO2 (ppt denotes parts per trillion, by volume). Typical maximum (local noontime) levels were 7.9×105 molecule cm-3 and 1.50 ppt for OH and HO2 respectively. The main sources of HOx were photolysis of O3 and HCHO, with potentially important but uncertain contributions from HONO and higher aldehydes. Of the measured OH sinks, reaction with CO and CH4 dominated, however comparison of the observed OH concentrations with those calculated via the steady state approximation indicated that additional co-reactants were likely to have been present. Elevated levels of NOx resulting from snowpack photochemistry contributed to HOx cycling and enhanced levels of OH, however the halogen oxides IO and BrO dominated the CH3O2-HO2-OH conversion in this environment, with associated ozone destruction. |
| URL | http://www.atmos-chem-phys.net/7/4171/2007/acp-7-4171-2007.pdf |
| Publication Type | journal article |
| Record ID | 62005046 |