Sensitivity of simulated climate to latitudinal distribution of solar insolation reduction in solar radiation management
Solar radiation management (SRM) geoengineering has been proposed as a potential option to counteract climate change. We perform a set of idealized geoengineering simulations using Community Atmosphere Model version 3.1 developed at the National Center for Atmospheric Research to investigate the gl...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-08-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/14/7769/2014/acp-14-7769-2014.pdf |
| Summary: | Solar radiation management (SRM) geoengineering has been proposed as a
potential option to counteract climate change. We perform a set of idealized
geoengineering simulations using Community Atmosphere Model version 3.1
developed at the National Center for Atmospheric Research to investigate the global
hydrological implications of varying the latitudinal distribution of solar
insolation reduction in SRM methods. To reduce the solar insolation we have
prescribed sulfate aerosols in the stratosphere. The radiative forcing in
the geoengineering simulations is the net forcing from a doubling of
CO<sub>2</sub> and the prescribed stratospheric aerosols. We find that for a fixed
total mass of sulfate aerosols (12.6 Mt of SO<sub>4</sub>), relative to a uniform
distribution which nearly offsets changes in global mean temperature from a
doubling of CO<sub>2</sub>, global mean radiative forcing is larger when aerosol
concentration is maximum at the poles leading to a warmer global mean
climate and consequently an intensified hydrological cycle. Opposite changes
are simulated when aerosol concentration is maximized in the tropics. We
obtain a range of 1 K in global mean temperature and 3% in precipitation
changes by varying the distribution pattern in our simulations: this range
is about 50% of the climate change from a doubling of CO<sub>2</sub>. Hence,
our study demonstrates that a range of global mean climate states,
determined by the global mean radiative forcing, are possible for a fixed
total amount of aerosols but with differing latitudinal distribution.
However, it is important to note that this is an idealized study and thus
not all important realistic climate processes are modeled. |
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| ISSN: | 1680-7316 1680-7324 |