Publication Abstracts

LeGrande and Schmidt 2008

LeGrande, A.N., and G.A. Schmidt, 2008: Ensemble, water-isotope enabled, coupled general circulation modeling insights into the 8.2-kyr event. Paleoceanography, 23, PA3207, doi:10.1029/2008PA001610.

Freshwater forcing has long been postulated as a catalyst for abrupt climate change due to its potential to interfere with thermohaline circulation (THC). The most recent example may have occurred about 8.2-kyr ago with the sudden drainage of glacial Lakes Agassiz and Ojibway into the Hudson Bay. We perform an ensemble of simulations for this freshwater release using the fully coupled atmosphere ocean general circulation model (GCM), GISS ModelE-R. In all cases, simulated effects include reduced ocean heat transport and enhanced atmospheric heat transport in the Atlantic, increased surface albedo (through greater low cloud and sea ice cover), and local cooling of up to 3°C. Our suite of ensemble experiments allows us to examine the importance of the initial ocean state, in particular the presence or absence of Labrador Sea Water, in controlling the magnitude and length of the climate response. Water isotope tracers included in this model provide an improved means for direct comparisons of the modeled tracer response to water isotope based, climate proxy data. Comparison of model simulations to data implies that there was an abrupt approximate halving of Atlantic THC, hence providing strong support for the hypothesis that the 8.2-kyr event was caused by an abrupt release of freshwater into the North Atlantic.

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BibTeX Citation

@article{le06200v,
  author={LeGrande, A. N. and Schmidt, G. A.},
  title={Ensemble, water-isotope enabled, coupled general circulation modeling insights into the 8.2-kyr event},
  year={2008},
  journal={Paleoceanography},
  volume={23},
  pages={PA3207},
  doi={10.1029%2F2008PA001610},
}

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RIS Citation

TY  - JOUR
ID  - le06200v
AU  - LeGrande, A. N.
AU  - Schmidt, G. A.
PY  - 2008
TI  - Ensemble, water-isotope enabled, coupled general circulation modeling insights into the 8.2-kyr event
JA  - Paleoceanography
VL  - 23
SP  - PA3207
DO  - 10.1029%2F2008PA001610
ER  -

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