Implementation of aerosol–cloud interactions in the regional atmosphere–aerosol model COSMO-MUSCAT(5.0) and evaluation using satellite data
The regional atmospheric model Consortium for Small-scale Modeling (COSMO) coupled to the Multi-Scale Chemistry Aerosol Transport model (MUSCAT) is extended in this work to represent aerosol–cloud interactions. Previously, only one-way interactions (scavenging of aerosol and in-cloud chemistry) a...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-06-01
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| Series: | Geoscientific Model Development |
| Online Access: | http://www.geosci-model-dev.net/10/2231/2017/gmd-10-2231-2017.pdf |
| Summary: | The regional atmospheric model Consortium for Small-scale Modeling
(COSMO) coupled to the Multi-Scale Chemistry Aerosol Transport model (MUSCAT)
is extended in this work to represent aerosol–cloud interactions. Previously,
only one-way interactions (scavenging of aerosol and in-cloud chemistry) and
aerosol–radiation interactions were included in this model. The new version
allows for a microphysical aerosol effect on clouds. For this, we use the
optional two-moment cloud microphysical scheme in COSMO and the
online-computed aerosol information for cloud condensation nuclei concentrations
(<i>C</i><sub>ccn</sub>), replacing the constant <i>C</i><sub>ccn</sub> profile. In the
radiation scheme, we have implemented a droplet-size-dependent cloud optical
depth, allowing now for aerosol–cloud–radiation interactions. To evaluate the
models with satellite data, the Cloud Feedback Model Intercomparison Project
Observation Simulator Package (COSP) has been implemented. A case study has
been carried out to understand the effects of the modifications, where the
modified modeling system is applied over the European domain with a
horizontal resolution of 0.25° × 0.25°. To reduce the
complexity in aerosol–cloud interactions, only warm-phase clouds are
considered. We found that the online-coupled aerosol introduces significant
changes for some cloud microphysical properties. The cloud effective radius
shows an increase of 9.5 %, and the cloud droplet number concentration is
reduced by 21.5 %. |
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| ISSN: | 1991-959X 1991-9603 |