Abstract:

Part I: Extratropical cyclone activity: historical and possible future changes
This part of the presentation is based on cyclones identified using an objective cyclone tracking algorithm. First, an inter-comparison of extratropical cyclone activity in nine global reanalysis datasets for the periods since 1900 or later will be presented. The inter-comparison reveals temporal homogeneity issues, similarity and disparity of the reanalysis datasets. In particular, all the four datasets that cover the period from1958 to 2010 agree well in terms of trend direction and interannual variability in hemispheric counts of deep-cyclones, showing a general increase in both hemispheres over the past half century, although the magnitude of increase varies notably from dataset to dataset. Then, possible future changes in cyclone activity as projected by the 11 CMIP5 models will be presented.

Part II: Historical and possible future changes of ocean surface waves in the East and South China Seas
This part of the presentation includes historical changes of ocean surface wave heights in the East and South China Seas over the period 1911-2010 as reconstructed using the Twentieth Century Reanalysis ensemble of mean sea level pressure (SLP) fields, and possible future changes in these study areas as projected by the WaveWatchIII model forced with surface winds simulated by five CMIP5 models for the RCP8.5 scenarios. The results show that, in both study areas, the 1911–2010 wave height trends are dominantly negative, with the exception that the seasonal maximum significant wave heights seem to have increased in summer and spring in the central South China Sea and in summer in the East China Sea. Such historical trends are projected to continue into the late 21st century.

Bio:
Xiaolan Wang obtained her PhD degree from University of Lisbon in 1995. She joined Environment Canada first as a postdoctoral fellow in 1996, then as a public servant in 1999. Now she is a senior research scientist (the highest level) at Climate Research Division, Science and Technology Branch, Environment and Climate Change Canada. Her expertise is in developing and using advanced statistical methods for climate research, including climate data homogenization and integration, trends and variability analysis, and extreme analysis including storm climate and variability, and ocean surface wave modelling. She is writing a book titled “Changepoint Detection, Data Homogenization, and Trend Analysis in Climate Research”, which will be published by Cambridge University Press, Cambridge University, United Kingdom.