HR: 10:20h
AN: PP51D-01 INVITED [PDF]
TI: The 1810s as an ideal test of climate model skill in predictability
AU: * Hyde, T J
EM: tcrowley@duke.edu
AF: Duke University, Dept. of Earth and Ocean Sciences
Box 90227, Durham, NC 27708 United States
AU: Hyde, W T
EM: wthyde@duke.edu
AF: Duke University, Dept. of Earth and Ocean Sciences
Box 90227, Durham, NC 27708 United States
AB:
One of the goals of paleo-research is to provide better constraints on our ability to understand the causes and consequences
of climate change. The 1810s may represent an ideal case for such studies. It was the coldest decade of the last 300 years
and climate models suggest that on the hemispheric scale the temperature changes were driven by a linear response to two very
large eruptions in 1809 (Unknown) and 1815 (Tambora). Because the large scale can be simulated so well it is of interest to
examine the regional response to such large scale forcing changes, for such a response represents a very useful target for
GCM modeling groups to assess skill in regional predictability. An analysis of the Mann et al. data set indicates that the
regional response from 1809-1818 was by no means uniform. Peak cooling occurred in eastern North America and the North
Atlantic sector. The response in the Pacific sector was relatively mild; the reconstruction for the Pacific Northwest
suggest a PNA type pattern associated with an upper level ridge that would account for such warmth and also the severity of
the downstream cooling over eastern North America and the North Atlantic. There is also some indication of relatively
mild/warm SSTs in the eastern North Pacific. These results indicate that the large circulation response translated the
radiative forcing perturbation into one of the dominant modes of the extratropical Northern Hemisphere circulation. Future
studies focusing on the GCM response over this interval would provide a valuable test on a model's ability to predict the
regional response to future greenhouse gas perturbations.
DE: 3309 Climatology (1620)
DE: 3344 Paleoclimatology
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting