1 / 19

Observed Changes in Climate Extremes in Canada

Observed Changes in Climate Extremes in Canada. Xuebin Zhang Climate Research Branch. What do we mean by extremes. Anything unusual, causing impacts Indices easy to compute Traditional indices Indices used by ETCCD Others. Trend identification. Methods Kendall-tau non-parametric method

duaa
Download Presentation

Observed Changes in Climate Extremes in Canada

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Observed Changes in Climate Extremes in Canada Xuebin Zhang Climate Research Branch

  2. What do we mean by extremes • Anything unusual, causing impacts • Indices easy to compute • Traditional indices • Indices used by ETCCD • Others

  3. Trend identification • Methods • Kendall-tau non-parametric method • No distributional assumption • Robust against outlier • GLM framework • Different distributions • Software available • Compute changes in extremes (e.g. return value)

  4. Lucie Vincent

  5. Lucie Vincent

  6. Lucie Vincent

  7. Trend in the Number of Spells Changes in cold spells and significant increases in warm spells in western Canada. Significant increases in cold spells in eastern Canada. Amir Shabbar

  8. Trend in the Duration of Spells Generally, longer warm spells in western Canada. Longer cold spells and shorter warm spells in eastern Canada. Amir Shabbar

  9. The 11-yr moving averages of annual time series of average number of heavy events per location over Canada south of 70N show strong decadal variability.

  10. Trends and their 95% confidence intervals in averaged normalized percentiles of annual daily precip, annual daily maximum, number of days with precip, and average precip rate during the 20th century.

  11. Conclusions • It is not getting hotter, it’s getting less cold • More warming in cold half of the year than warm half • More warming in daily minimum than daily maximum • Reduced frequency of coldest daily T

  12. Conclusions • It’s not raining harder, it rains more often • No upward trends in the frequency/magnitude of heavy daily P events • Increased annual total precip due to more days with precip • Average rain rate decreased • Regional/seasonal differences

  13. Papers • Zhang,X., F.W. Zwiers, and G. Li, 2003: Monte Carlo experiments on the detection of trends in extreme values, J. Climate (submitted) • Shabbar, A., and B. Bonsal, 2003: An assesment of changes in winter cold and warm spells over Canada. Natural Hazards, 29, 173-188. • Zhang, X., Hogg, W. D., and Mekis, E., 2001: Spatial and temporal characteristics of heavy precipitation events in Canada. J. Climate. 14, 1923-1936. • Bonsal, B., Zhang, X., Vincent, L., Hogg, W.D., 2001: Characteristics of daily and extreme temperatures over Canada. J. Climate, 14, 1959-1976 • Zhang, X., Harvey, K. D., Hogg, W. D., Yuzyk, T. R., 2000: Trends in Canadian Streamflow. Water Resources Research, 37, 987-998.

More Related