Transient Climate Simulation of the last deglaciation in CCSM3
- ORNL
- Argonne National Laboratory (ANL)
We conducted the first synchronously coupled atmosphere-ocean general circulation model simulation of global climate evolution of the last deglaciation (21,000-10,000 years ago) using the NCAR CCSM3. With realistic climate forcings associated with greenhouse gasses, orbital forcing and continental ice sheet, as well as a reasonable melting water forcing, our model reproduces some major deglacial climate features, such as the H1 event, the BA warming and the YD event. A preliminary model-data comparison shows a global climate evolution largely consistent with the reconstruction. The magnitude of our model climate responses are largely consistent with the reconstruction, suggesting a good agreement between observed and modeled climate sensitivity. In contrast to previous simulations of intermediate climate models, our model AMOC has little hysteresis. As a result, the model simulates the abrupt onset of the BA warming and the abrupt termination of the YD cooling as transient responses of the Atlantic meridional overturning circulation (AMOC) to abrupt terminations of freshwater discharges. Further implications to transient model-data comparison will also be discussed.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 982158
- Resource Relation:
- Conference: AGU Fall Meeting, San Francisco, CA, USA, 20091214, 20091214
- Country of Publication:
- United States
- Language:
- English
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