 |
| Titel |
Modelling of nitrate and ammonium-containing aerosols in presence of sea salt |
| VerfasserIn |
G. Myhre, A. Grini, S. Metzger |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 6, no. 12 ; Nr. 6, no. 12 (2006-10-25), S.4809-4821 |
| Datensatznummer |
250004155
|
| Publikation (Nr.) |
 copernicus.org/acp-6-4809-2006.pdf |
|
|
|
|
|
| Zusammenfassung |
| A thermodynamical model for treatment of gas/aerosol partitioning of semi
volatile inorganic aerosols has been implemented in a global chemistry and
aerosol transport model (Oslo CTM2). The sulphur cycle and sea salt
particles have been implemented earlier in the Oslo CTM2 and the focus of
this study is on nitrate partitioning to the aerosol phase and if
particulate nitrate is expected to form in fine or coarse mode aerosols.
Modelling of the formation of fine mode nitrate particles is complicated
since it depends on other aerosol components and aerosol precursors as well
as meteorological condition. The surface concentrations from the model are
compared to observed surface concentrations at around 20 sites around Europe
for nitrate and ammonium. The agreement for nitrate is good but the modelled
values are somewhat underestimated compared to observations at high
concentrations, whereas for ammonium the agreement is very good. However, we
underscore that such a comparison is not of large importance for the aerosol
optical depth of particulate nitrate since the vertical profile of aerosol
components and their precursors are so important. Fine mode nitrate
formation depends on vertical profiles of both ammonia/ammonium and
sulphate. The model results show that fine mode particulate nitrate play a
non-negligible role in the total aerosol composition in certain
industrialized regions and therefore have a significant local radiative
forcing. On a global scale the aerosol optical depth of fine mode nitrate is
relatively small due to limited availability of ammonia and loss to larger
sea salt particles. Inclusion of sea salt in the calculations reduces the
aerosol optical depth and burden of fine mode nitrate by 25% on a global
scale but with large regional variations. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|