 |
| Titel |
The characterisation of pollution aerosol in a changing photochemical environment |
| VerfasserIn |
M. J. Cubison, M. R. Alfarra, J. Allan, K. N. Bower, H. Coe, G. B. McFiggans, J. D. Whitehead, P. I. Williams, Q. Zhang, J. L. Jimenez, J. Hopkins, J. Lee |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 6, no. 12 ; Nr. 6, no. 12 (2006-12-13), S.5573-5588 |
| Datensatznummer |
250004205
|
| Publikation (Nr.) |
 copernicus.org/acp-6-5573-2006.pdf |
|
|
|
|
|
| Zusammenfassung |
| Measurements are presented from a sampling location 50 km downwind of
Greater London, UK, to investigate the timescales required for the
atmospheric transformations of aerosol in urban emissions plumes in the
context of photochemical age based on the benzene to toluene ratio. It is
shown that particles at or around 100 nm in diameter exhibit the greatest
systematic variability in chemical properties, and thus hygroscopic
properties, on a timescale of 1–2 days. The smaller Aitken mode and larger
accumulation mode particles exhibit less variability on these timescales,
which we propose is as a result of their different residence times in the
atmosphere. The larger accumulation particles have been in the atmosphere
longer than the 100 nm particles and their chemistry and hygroscopic
properties have been integrated over several days and potentially over
several source regions. In contrast, the smaller Aitken mode particles show
little systematic variability with photochemical age because their
atmospheric lifetimes are short, thus chemical changes and hence changes in
water affinity have not had time to occur. Increases in the particle
diameter of up to 40% are observed at 90% relative humidity in the
accumulation mode from the uptake of water as the particles become
increasingly soluble in nature. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|