Impact of organic soil on the high-latitude surface/sub-surface climate characteristics

Friday, 19 December 2014
Laxmi Sushama, University of Quebec at Montreal UQAM, Montreal, QC, Canada
This study focuses on the impact of organic soil on the simulated soil thermal and moisture regimes and on the surface climate, for the high-latitude regions, for the current 1981–2010 and future 2071–2100 periods. Two simulations, spanning the 1950–2100 period, are performed with the fifth generation of the Canadian Regional Climate Model (CRCM5), with and without organic soil, over a pan-Arctic domain. These simulations are driven by the Canadian Earth System Model (CanESM2) at the lateral boundaries, and correspond to representative concentration pathway 8.5. Comparison of the two simulations, for the current and future periods, suggests significant impact of organic soil on the sub-surface climate, including the active layer thickness and therefore the regional hydrology for the permafrost regions. The impact of organic soil on the CRCM5 simulated surface climate is modest for the current period, but appear amplified for the future period for the RCP scenario considered in this study. This study thus demonstrates the important linkages between organic soil and the regional climate characteristics.