91Ë¿¹ÏÊÓƵ

Better representation of land processes and land heterogeneity in climate models is key to realistic energy and water partitioning at the surface, and is therefore important to improve the realism of the surface climate and hydrology. The representation of land processes was improved in the CRCM through the incorporation of a number of land modules, under herÌýguidance. These include interactive modelling of near surface permafrost, lakes and dynamic vegetation that are very important for the Canadian high- latitudes. These implementations have enabled better comprehension of land-climateÌýinteractions in the Canadian high-latitudes and led to a number of invited talks at international events such as EGU, Entretiens Jacques Cartier, and the international summer school on climate variability and climate change. This improved model is currently being used by Ouranos Consortium, for producing transient climate change simulations to support impact and adaptation studies of various provincial and government bodies/sectors, as well as private industries.Ìý

This first ever Canada-wide study to assess projected changes to water resources using regional climate model projections was led by Dr. Sushama. Provision of detailed nation-wide information of climate-change impacts on water resources and estimates of future water availability, based on an ensemble of state-of-the-art RCMs was an important deliverable of this project. In particular, the study provided first hand information on projected changes to number of dry/wet days, short and long dry spells, precipitation extremes and low- and high-flows. These results were communicated to the climate impacts community and made available for further study into the ecological and social consequences of these changes. This project led to further strengthening the collaborations with HydroQuebec and Manitoba Hydro.Ìý

A number of studies, including those undertaken under herÌýguidance, suggest an increase in the frequency and intensity of temperature and precipitation extremes over Canada. The physical mechanisms underlying such changes may relate to changes in large-scale circulation and/or changes in processes such as soil moisture-atmosphere interactions. Under Dr. Sushama's guidance, efforts were deployed to understand the role of land state, particularly soil moisture, in modulating temperature and precipitation extremes over Canada. This led to the identification of hotspots of land-atmosphere coupling over the region, and its inter-seasonal and inter-annual variability and projected changes in future climate. This is crucial information for developing adaptation strategies, particularly for the development of early warning and prediction tools for temperature and precipitation extremes.Ìý

RCMs are associated with various sources of uncertainties, which include (a) structural uncertainty associated with model formulation, (b) internal variability (triggered by differences in the initial conditions), and (c) dependence on boundary forcing (i.e. the driving GCM). A multi-RCM ensemble is essential to better quantify these uncertainties. The article by Monette et al. (2012), which focussed on the evaluation and assessment of future changes to single- and multi-day precipitation extremes over 21 selected north-east Canadian watersheds, using the NARCCAP multi-RCM ensemble and the Regional Frequency Analysis approach, proposed ways of quantifying these above mentioned uncertainties. This research thus contributed crucial information that will help HydroQuebec in its effort to better plan and adapt its hydroelectric power generation infrastructure in a changing climate.

Climate change, induced by increased anthropogenic emission of greenhouse gases, is being experienced particularly intensely in the Arctic, with Arctic average temperatures having risen at almost twice the rate of the rest of the world in the past few decades. TheÌýimpact of climate change on permafrost is very important as it can change the hydrology for the region significantly. The very first study over Canada to understand projected changes to the soil thermal and moisture regimes was undertaken by Sushama et al. (2006). Though the model used was simple, it gave some important ideas as to what to expect in a changing climate. This research attracted great attention from both national and international researchers and Dr. Sushama was invited to give talks at Environment Canada in Downsview - Toronto, University of Alaska in Fairbanks, Ouranos Consortium and GEC3 based at 91Ë¿¹ÏÊÓƵ. This work has since then been expanded to address other scientific questions such as the impact of interactive phenology on permafrost and the regional hydrology using RCM experiments.