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| Titel |
Model - data integration with 18O water isotope: results for pre-industrial and Last Glacial Maximum climates |
| VerfasserIn |
Didier Roche, Thibaut Caley |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250077252
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| Zusammenfassung |
| Amongst the different proxies used in palaeoclimate studies, few are as routinely measured
since years in the different realms of the Earth system as are water isotopes. They
form the base for our understanding of marine sediment cores (marine carbonate
δ18O) and ice cores but are as well measured in lake sediments, corals, speleothems
or tree rings. Since the processes involved in building all these archives are quite
complex, it is often difficult to link the changes in one particular location to another
distant one if few reliable time markers are present. Since the δ18O is ultimately
controlled by the hydrological cycle in the atmosphere together with long term
response of the cryosphere – oceanic system, there is potential to use the physical
processes of δ18O to link the climate archives together. Our aim is to achieve such a
goal using a model-based approach, the model being a test bed for ideas of climate
evolution.
We present here the first part of our work that concerns the validation of the model under
pre-industrial conditions and Last Glacial Maximum simulation, after development of the
18O cycle within the iLOVECLIM coupled climate model (Roche and Caley, in
preparation).
For the pre-industrial climate, we present a proxy based evaluation of the model that arise
from a compilation of Late Holocene 18O data from the different Earth components. We
show that using a model with low resolution complicates certain aspects of the data – model
comparison on land, while we are able to fairly well represent the observed distribution of
18O within the oceans. We discuss some of the caveats in the view of what is (expected to be)
recorded in each archive.
Moving to the Last Glacial Maximum (21000 yrs), we analyse the simulated evolution as
compared to compiled databases (speleothems, ice cores and marine sediments, Caley and
Roche, in preparation) and existing simulations with isotope enabled models. We
focus our analysis on the detection of major front systems changes in the ocean and
on the link between oceanic circulation changes and its detection in land δ18O
change. |
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