Climate variability and changes in extratropical storm activities over the Hudson Bay area (Canada) : links with surface extremes and maritime infrastructures vulnerabilities

The objective of the present study is to support a vulnerability and adaptation study of the marine infrastructures in Nunavik (i.e. Hudson Bay area, Canada) to climate change. By improving the knowledge on water level variations, trajectories, the recurrence and intensity of storms, as well as on the risk and scale of extreme events to come, the main aim is to provide necessary data and advice that will help anticipate the impacts of climate change in order to optimize the maintenance program, define conservation and rehabilitation programs and improve users' safety along the Nunavik's coasts. This paper will present first an intercomparison of extratropical storms (i.e. tracks with their intensity, duration and frequency at intra-annual and inter-annual scales) developed or in moving over the Hudson Bay area, from regional and global reanalysis products (i.e. NARR and NCEP), regional climate models (RCMs, i.e. different versions of the Canadian RCM driven in reanalysis and in climate mode), and the Canadian forecast model (GEM) used as reference data series over the recent period. The results suggest that strong compatible storms are produced during the years by both the reanalysis products and regional climate/forecast models, except for the most intense events where more differences appear between models. The links between storms and the occurrence of surface extremes (i.e. temperatures and winds) are also explored using coastal observed weather stations over the 1979-2009 period. Those reveal large-scale and regional scale effects variously resolved by the range of analyzed models. Finally, the changes in storms are briefly analyzed using simulations of the CRCM driven by the Canadian coupled global climate model (CGCM3) under the IPCC-SRES A2 emission scenario over the 21st century.