 |
| Titel |
Real-case simulations of aerosol–cloud interactions in ship tracks over the Bay of Biscay |
| VerfasserIn |
A. Possner, E. Zubler, U. Lohmann, C. Schär |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 4 ; Nr. 15, no. 4 (2015-02-27), S.2185-2201 |
| Datensatznummer |
250119467
|
| Publikation (Nr.) |
 copernicus.org/acp-15-2185-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
Ship tracks provide an ideal test bed for studying aerosol–cloud
interactions (ACIs) and for evaluating their representation in model
parameterisations. Regional modelling can be of particular use for
this task, as this approach provides sufficient resolution to resolve
the structure of the produced track including their meteorological
environment whilst relying on the same formulations of
parameterisations as many general circulation models. In this work we
simulate a particular case of ship tracks embedded in an optically
thin stratus cloud sheet which was observed by a polar orbiting
satellite at 12:00 UTC on 26 January 2003 around the Bay of
Biscay.
The simulations, which include moving ship emissions, show that the
model is indeed able to capture the structure of the track at a
horizontal grid spacing of 2 km and to qualitatively capture the
observed cloud response in all simulations performed. At least a
doubling of the cloud optical thickness was simulated in all
simulations together with an increase in cloud droplet number
concentration by about 40 cm−3 (300%) and decrease in effective
radius by about 5 μm (40%). Furthermore, the ship emissions lead to an
increase in liquid water path in at least 25% of the track
regions.
We are confident in the model's ability to capture key processes of
ship track formation. However, it was found that realistic ship
emissions lead to unrealistic aerosol perturbations near the source
regions within the simulated tracks due to grid-scale dilution and
homogeneity.
Combining the regional-modelling approach with comprehensive field
studies could likely improve our understanding of the sensitivities
and biases in ACI parameterisations, and could therefore help to
constrain global ACI estimates, which strongly rely on these
parameterisations. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|