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| Titel |
Orbital interpolation methods for coupling GCMs to ice sheet models and potential impact on ice sheet hysteresis |
| VerfasserIn |
E. Gasson, D. Lunt, D. Pollard, M. Siddall |
| 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 |
250063429
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| Zusammenfassung |
| The computational expense of running GCMs and the long response times of ice sheets
presents a problem when modeling large ice sheet changes. Although a fully synchronous
coupling between GCMs and ice sheet models is desirable, when performing long duration
(105 – 107 year) transient simulations of paleoclimates this is currently not feasible. This
has led to the use of reduced or intermediate complexity climate models, climate
parameterizations, asynchronously coupled GCMs and GCM lookup tables to provide climate
forcing to ice sheet models.
The coupling of GCMs to ice sheet models using an asynchronous method
or a GCM lookup table requires interpolation of orbital variability from only a
few GCM runs, reducing the computational expense of running the GCM. There
are various methods for performing this interpolation. Orbital variability can be
based on a synthetic orbit, which reproduces the essence of orbital cycles, or on
reconstructions of the past orbit. If a reconstruction of the past orbit is used as a target, then a
number of GCM runs with different insolation can be optimized to reproduce this past
orbit.
We evaluate different methods for performing interpolation and optimization of orbital
variability for asynchronously coupled GCM and GCM lookup table approaches by modeling
the onset of continental sized Antarctic glaciation at the Eocene-Oligocene climate transition.
We suggest that these different methods for including orbital variability in long
duration transient simulations of ice sheets may have an impact on ice sheet hysteresis. |
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