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| Titel |
The importance of the mid Holocene for improving predictions of future climate change. |
| VerfasserIn |
J. C. Hargreaves, J. D. Annan  , R. Ohgaito, A. Abe-Ouchi |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250024314
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| Zusammenfassung |
| Much of the work to date within PMIP has been focussed on two particular paleoclimate
epochs, the Last Glacial Maximum (LGM, 21ka BP) and the mid Holocene (6ka BP). The
LGM climate was considerably cooler than the present day with large ice sheets and
significantly lower atmospheric carbon dioxide concentration. Since the signal-to-noise ratio
of the climate changes between LGM and present is relatively large, this epoch
has been widely used as a basis for understanding the behaviour of the climate
system and thus improving forecasts of future climate change. In contrast the global
forcing for the mid Holocene is rather close to that of today (albeit with seasonal and
regional differences), and studies demonstrating the usefulness of the period for
quantitatively constraining future climate have yet to emerge. As a first step in this area we
will present a comparative analysis of doubled CO2, LGM and the mid Holocene
climates using temperature and precipitation results from an ensemble of model runs
from MIROC3.2. We find that the potential usefulness of the the mid-Holocene for
predicting future changes forced by CO2 exceeds that of the LGM on select regional to
zonal scales, one example being the precipitation in the monsoon region. Although
correlations with proposed future climate change experiments remain relatively weak,
compared to that for global temperature change for LGM and future, the fact is
that changes in the precipitation in the monsoon region are of high importance,
and if the mid-Holocene is the most powerful paleoclimate epoch for this region,
further steps should be taken to improve the simulation of mid-Holocene monsoon
regions. |
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