Land Surface Scheme in CRCM5

1
Outline

• Land Surface Scheme in CRCM5
• Advanced modules
• Summary

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

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)

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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?
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Can a climate model with a shallow LSS be used to
model ALT and near surface permafrost?
Smerdon and Stieglitz (2006 GRL)
Lawrence et al. (2008) Nicolsky et al.
(2007) Alexeev et al. (2007)
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CRCM experiment with shallow and deep Soil Layers
3 layers
13 layers
(all 13 layers)
0.10 m
0.10 m
0.25 m
2.5 m
0.35 m
6.0 m
4.0 m
10.0 m
6.0 m
16.0 m
8.0 m
24.0 m
13.0 m
3.75 m
37.0 m
22.0 m
Max. depth to bedrock
59.0 m
4.10 m
4.10 m
36.0 m
Bedrock 0.10 m 3.60 m
95.0 m
95.0 m
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CRCM experiment with shallow and deep Soil Layers

• 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 1000-1990 and the profiles from 1961 were
  used as initial conditions for the experiments
  with the deeper version of CLASS3.4

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Seasonal means, 3 layer run 13 layer run
1st layer soil temperature
Sensible Heat Flux
2 meter temperature
W/m²
C
C
JJA 1979-2002
different scales!
W/m²
C
C
DJF 1978-2001
Source Katja Winger
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Organic soil
Distribution of organic soil
Organic soil has higher porosity and hydraulic
conductivity compared to mineral soils
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Organic soil
Simulated annual-mean temperature for the top
soil layer
3-layer No organic soil
3-layer with organic soil
Source Yanjun Jiao
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Other Modules in CRCM5 (multitude of surface
types)

• Lakes

• Hostetler and Flake models being implemented

The Lake Model Intercomparison Project (LakeMIP)
http//www.unige.ch/climate/lakemip/index.html
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Dynamic vegetation
Other Modules in CRCM5
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

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