Joint assembly AGU-GAC-MAC-CGU
Year of publication:
Land-atmosphere coupling was long thought not to be strong enough to have a profound effect on climatic conditions during colder months. Hence, while the impact of land-atmosphere coupling on summer is well documented, its impact on spring, winter and fall is less well established. In particular, soil moisture could be influenced by the considerable amount of snow/ice melt that occur during spring, which makes it an ideal season to investigate further. Here, we use the 5th generation Canadian Regional Climate Model (CRCM5) simulations, with and without land-atmosphere coupling, to evaluate the strength of land-atmosphere coupling and its influence on present and future climates over North America. Analysis of coupled and uncoupled simulations, that were run under present climatic conditions, reveal that soil moisture/temperature coupling over the Great Plains is stronger in spring compared to summer. It is also strong over the Canadian Prairies during the transition months between spring and summer. Some shifts in the timing and location of land-atmosphere coupling are noted in future climate. This paper will therefore address the seasonal evolution of land-atmosphere coupling, underlying mechanisms and its impact on extremes over North America.