11.8
A Physically-Consistent Long-term Reconstruction of the Northern Annular Mode Using Tree Rings
Justin J. Wettstein, University of Washington, Seattle, WA; and J. M. Wallace
The Northern Annular Mode (closely related to the North Atlantic Oscillation) has a robust wintertime signature in surface temperature and precipitation. Select tree ring width site chronologies are shown to adequately record local environmental conditions during winter in regions where the Northern Annular Mode surface temperature signal is especially strong. Site chronologies are thereby used to generate a simple, yet robust, long-term reconstruction of the Northern Annular Mode. Cross-validated results for the reconstruction compare favorably with existing studies and are straightforward to physically interpret. Extension of this work to consider other annually-resolved paleoclimatic data may more clearly document the evolution of northern hemisphere climate variability over a timeframe of the most recent several hundred to thousand years.
Session 11, Observed Seasonal/Interannual Variability (Room 608)
Thursday, 15 January 2004, 11:00 AM-3:00 PM, Room 608
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