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| Titel |
Global sensitivity analysis of GCMs to astronomical forcing, CO2 and ice volume |
| VerfasserIn |
N. Bounceur, P. Araya-Melo, M. Crucifix |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250062288
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| Zusammenfassung |
| We propose a global sensitivity analysis of the climate simulated by General Circulation
Models of the Atmosphere and Ocean (AOGCM), to the astronomical forcing, CO2
and ice sheet topography and volume. Our purpose is to determine the structural
properties of the models response, and in particular identify, in a systematic fashion,
non-linear behaviours resulting from the combination of different components of the
forcing.
In principle, exploring fully the input space would require thousands of simulations. The
solution adopted here relies on the construction of a statistical surrogate, called emulator.
This emulator is calibrated on a moderate number of experiments (typically 20 to 50), chosen
using a MaxiMinLatin hypercube design. The emulator provides both an estimate of the
model at untried, arbitrary inputs, and quantifies uncertainty associated with the fact this is
an emulator instead of the full simulator. The emulator chosen here is a Gaussian
process.
The emulator is here is expressed in a reduced output space made of the principal modes
of the climate variability, extracted using a principal component analysis on seasonal mean
surface temperature and seasonal mean precipitation. The methodology is applied to two
simulators : LOVECLIM and HadCM3. |
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