1 o Land Surface Scheme in CRCM5 o Advanced modules o Summary Outline

2 Overview: Land surface scheme in CRCM Thermally separate vegetation canopy, snow cover and three soil layers (0.1, 0.25, 3.75m). Four main vegetation structural types identified (needleleaf trees, broadleaf trees, crops and grass) Up to four subareas allowed for land surface type: vegetation covered, bare soil, snow with vegetation and snow over bare soil One soil type for each grid cell Canadian LAnd Surface Scheme; Verseghy, 1991; Verseghy et al., 1993 Verseghy, 2000

3 Enhanced features  Option for deeper soil configuration  Ability to model organic soils  Optional mosaic formulation  Ability to model lateral movement of soil water  Enhanced snow density and snow interception

4 Recent interest in permafrost  Permafrost degradation can have adverse impacts on socio-economic and eco-environmental systems  Climate model projections indicate a rise in the global average temperatures over the next century (IPCC, 2007) Drunken forest in Siberia

5 Permafrost (offline) Modelling Drawback: Cannot capture the land/atmosphere feedbacks Can a climate model with a shallow LSS be used to model ALT and near surface permafrost? 0 – 6 m Simulated average ALT for current and future climates 0 – 9 m Sushama et al. (2006)

6 Can a climate model with a shallow LSS be used to model ALT and near surface permafrost? Infinite half space3m thick slab with zero flux boundary condition Smerdon and Stieglitz (2006; GRL) Lawrence et al. (2008) Nicolsky et al. (2007) Alexeev et al. (2007)

7 CRCM experiment with shallow and deep Soil Layers 3 layers 0.10 m 0.35 m 4.10 m 0.10 m 0.25 m 3.75 m 10.0 m 16.0 m 24.0 m 37.0 m 59.0 m 95.0 m 6.0 m 4.0 m 6.0 m 8.0 m 13.0 m 22.0 m 36.0 m 2.5 m 13 layers (all 13 layers) Bedrock: 0.10 m – 3.60 m Max. depth to bedrock 4.10 m 95.0 m

8 Soil Initial conditions Stevens et al. (2008) forward modelled the ECHO-g simulated, millenial, paleoclimatic histories to obtain the sub-surface thermal profiles, which were validated over North-America, against available borehole measurements The above forward modelling was done for the period and the profiles from 1961 were used as initial conditions for the experiments with the deeper version of CLASS3.4 CRCM experiment with shallow and deep Soil Layers

9 JJA DJF °C Seasonal means, 3 layer run – 13 layer run °C W/m² 1 st layer soil temperature Sensible Heat Flux2 meter temperature different scales! Source: Katja Winger

10 Organic soil Distribution of organic soil Organic soil has higher porosity and hydraulic conductivity compared to mineral soils

11 3-layer: No organic soil 3-layer: with organic soil Simulated annual-mean temperature for the top soil layer Source: Yanjun Jiao Region with organic soil Inclusion of the organic soil parameterization leads to much cooler temperatures Organic soil

12 Other Modules in CRCM5 (multitude of surface types) Lakes - Hostetler and Flake models being implemented The Lake Model Intercomparison Project (LakeMIP):

13 Dynamic vegetation Canadian Terrestrial Ecosystem Model (Arora, 2003) Photosynthesis Autotrophic respiration Heterotrophic respiration Phenology Turn over of live veg, Mortality Allocation Disturbance due to fire, Land use related carbon emissions Other Modules in CRCM5

14 River-Lake system model Routing models: WATRoute Variable velocity (Arora and Boer, 1999; Lucas-Picher, 2003) Variable lag (Sushama et al., 2004)

15 Summary CLASS: LSS in the Canadian RCM Features required for high-latitude regions Upcoming modules Opportunities to test/share/use modules Yet to come …. Thermokarst, glaciers, icesheets, ……