Uptake of NO3 and N2O5 to Saharan dust, ambient urban aerosol and soot: a relative rate study
Item
Title (Dublin Core)
Uptake of NO3 and N2O5 to Saharan dust, ambient urban aerosol and soot: a relative rate study
Description (Dublin Core)
The uptake of NO<sub>3</sub> and N<sub>2</sub>O<sub>5</sub> to Saharan dust, ambient aerosols and soot was investigated using a novel and simple relative rate method with simultaneous detection of both NO<sub>3</sub> and N<sub>2</sub>O<sub>5</sub>. The use of cavity ring down spectroscopy to detect both trace gases enabled the measurements to be carried out at low mixing ratios (<500 pptv or 1×10<sup>10</sup> molecule cm<sup>−3</sup>). The uptake coefficient ratio, γ(NO<sub>3</sub>)/γ(N<sub>2</sub>O<sub>5</sub>), was determined to be 0.9±0.4 for Saharan dust, independent of relative humidity, NO<sub>3</sub> or N<sub>2</sub>O<sub>5</sub> mixing ratio and exposure time. Ambient (urban) aerosols showed a very limited capacity to take up N<sub>2</sub>O<sub>5</sub> but were reactive towards NO<sub>3</sub> with γ(NO<sub>3</sub>)/γ(N<sub>2</sub>O<sub>5</sub>)>15. A value of γ(NO<sub>3</sub>)/γ(N<sub>2</sub>O<sub>5</sub>)~1.5–3 was obtained when using candle generated soot. The relative rate obtained for Saharan dust can be placed on an absolute basis using our recently determined value of γ(N<sub>2</sub>O<sub>5</sub>)=1×10<sup>−2</sup> to give γ(NO<sub>3</sub>)=9×10<sup>−3</sup>, which is significantly smaller than the single previous value. With the present uptake coefficient, reaction of NO<sub>3</sub> with mineral dust will generally not contribute significantly to its NO<sub>3</sub> loss in the boundary atmosphere or to the nitration of mineral dust.
Creator (Dublin Core)
Tang, M. J.
Thieser, J.
Schuster, G.
Crowley, J. N.
Date (Dublin Core)
2018-01-15
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-10-2965-2010
https://acp.copernicus.org/articles/10/2965/2010/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
