Uptake of HO2 radicals on Arizona Test Dust
Item
Title (Dublin Core)
Uptake of HO2 radicals on Arizona Test Dust
Description (Dublin Core)
The interaction of HO<sub>2</sub> radicals with solid films of Arizona Test Dust (ATD) was studied using a low-pressure flow reactor (1–9 Torr) combined with a modulated molecular beam mass spectrometer for monitoring of the gaseous species involved. The reactive uptake coefficient of HO<sub>2</sub> was measured from the kinetics of HO<sub>2</sub> consumption on Pyrex rods coated with ATD as a function of HO<sub>2</sub> concentration ((0.35–3.30) × 10<sup>12</sup> molecule cm<sup>−3</sup>), relative humidity (RH = 0.02–94%), temperature (<i>T</i> = 275–320 K) and UV irradiance intensity (<i>J</i><sub>NO<sub>2</sub></sub> = 0–0.012 s<sup>−1</sup>). The initial uptake coefficient was found to be independent of concentration of HO<sub>2</sub>, temperature and irradiation conditions, and to decrease with increasing relative humidity: γ<sub>0</sub> = 1.2/(18.7 + RH<sub>1.1</sub>) (with 30% estimated conservative uncertainty). The uptake coefficient was calculated using geometric surface area and should be considered as an upper limit of γ<sub>0</sub>. An upper limit of 5% was found for the gaseous H<sub>2</sub>O<sub>2</sub>-forming pathway of the HO<sub>2</sub> reaction with ATD surface. The results of the measurements indicate that HO<sub>2</sub> loss on dust aerosol may be a non-negligible sink for HO<sub>x</sub> species in the troposphere with the effect depending on specific local conditions.
Creator (Dublin Core)
Bedjanian, Y.
Romanias, M. N.
Zein, A.
Date (Dublin Core)
2018-01-15
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-13-6461-2013
https://acp.copernicus.org/articles/13/6461/2013/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
