14.1
Planetary circulation and Canadian temperature trends
Xuebin Zhang, MSC, Downsview, ON, Canada; and J. Sheng and W. D. Hogg
The association between trends in Canadian temperature and changes in the planetary circulation over the Northern Hemisphere has been investigated. A principal component analysis was performed on the sea level pressure of the Northern Hemisphere, and the first 6 principal components were retained as predictors. Multiple linear regressions were then established between gridded temperature anomalies and the predictors to reconstruct temperature anomalies based on a cross-validation framework. Trends were finally computed for the original and reconstructed temperatures. The results suggest that 50-80% of observed trends in annual, winter, and spring mean temperatures and a considerable portion of trends in summer and autumn temperatures can be associated with the variations of the planetary circulation. They also indicate that the circulation patterns that are linked to Arctic Oscillation and Pacific Decadal Oscillation mainly influence temperature trends over northeast and southwest, respectively.
Session 14, Observed Variability and Change: Surface Part I (Parallel with Sessions 11 & 13)
Wednesday, 17 January 2001, 3:30 PM-5:00 PM
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