 |
| Titel |
Multi-phase halogen chemistry in the tropical Atlantic Ocean |
| VerfasserIn |
R. Sommariva, R. von Glasow |
| Konferenz |
EGU General Assembly 2012
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250065917
|
|
|
|
|
|
| Zusammenfassung |
| We used a one-dimensional model to simulate the chemical evolution of air masses in the
eastern tropical Atlantic Ocean (Cape Verde region), with a focus on halogen chemistry. The
model results were compared to the observations of inorganic halogen (particularly chlorine
and bromine) species made in this region. The model could reproduce the measurements of
chlorine species, especially under unpolluted conditions, but it overestimated sea-salt chloride
and bromine species. Agrement with the measurements could be improved by taking into
account the reactivity with aldehydes and the effects of DMS and Saharan dust on aerosol
pH; an hypothetical HOX -> X- aqueous-phase reaction could also improve the
agreement with measured Cl2 and HOCl, particularly under semi-polluted conditions.
The results showed that halogen levels and speciation are very sensitive to cloud
processing, although the model could not reproduce the observations under cloudy
conditions. The model results were used to calculate the impact of the observed levels
of halogens: Cl accounted for 5.4 - 11.6% of total methane sinks and halogens
(mostly bromine and iodine) accounted for 35 - 40% of total ozone destruction. |
|
|
|
|
|
|