Global response of parameterised convective cloud fields to anthropogenic aerosol forcing
<p>The interactions between aerosols and convective clouds represent some of the greatest uncertainties in the climate impact of aerosols in the atmosphere. A wide variety of mechanisms have been proposed by which aerosols may invigorate, suppress or change the properties of individual convect...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-04-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/20/4445/2020/acp-20-4445-2020.pdf |
| Summary: | <p>The interactions between aerosols and convective clouds represent some of the
greatest uncertainties in the climate impact of aerosols in the atmosphere. A
wide variety of mechanisms have been proposed by which aerosols may
invigorate, suppress or change the properties of individual convective
clouds, some of which can be reproduced in high-resolution limited-area
models. However, there may also be mesoscale, regional or global adjustments
which modulate or dampen such impacts which cannot be captured in the limited
domain of such models. The Convective Cloud Field Model (CCFM) provides a
mechanism to simulate a population of convective clouds, complete with
microphysics and interactions between clouds, within each
grid column at resolutions used for global climate modelling, so that a
representation of the microphysical aerosol response within each parameterised
cloud type is possible.</p>
<p>Using CCFM within the global aerosol–climate model ECHAM–HAM, we
demonstrate how the parameterised cloud field responds to the present-day
anthropogenic aerosol perturbation in different regions. In particular, we
show that in regions with strongly forced deep convection and/or significant
aerosol effects via large-scale processes, the changes in the convective cloud
field due to microphysical effects are rather small; however in a more
weakly forced regime such as the Caribbean, where large-scale aerosol effects
are small, a signature of convective invigoration does become apparent.</p> |
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| ISSN: | 1680-7316 1680-7324 |