Download ASM_Terrestrial_Carbon_AGS

Model Intercomparisons and Validation:
Terrestrial Carbon, an Arctic Emphasis
Andrew Slater
Carbon Model Intercomparisons
• EDMI – offline
• C4MIP – C-Model and parent Atmosphere
• C-LAMP – C-Model and CAM (CCSM Atmo)
• IPCC AR5 – The next big thing …..
Ecosystem Dynamics Model Intercomp.
C4MIP – Carbon Cycle & Climate Change
• 11 Models (International effort)
o
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Coupled Atmo-Ocean-Land + Carbon GCMs
Numerous carbon pools in models
Generally fixed Q10 values (global)
No nitrogen cycle included
• Simulations with & without interactive CO2
• Later found that Nitrogen limitation would
decrease carbon uptake
C4MIP - Results
• No consensus on total NPP response to Climate Change
o
o
↑T + ↑CO2 → ?
Will the land be a sink or source?
• Carbon uptake ability decreases
o
↑T → ↓CO2 uptake
Carbon-Land Model Intercomparison Project
• Couple 3 models to the CCSM atmosphere
 CLM3-CASA’
 CLM3-CN
 LSX-IBIS
• Multi-criteria objective function
• Aids model development & selection
Carbon-Land Model Intercomparison Project
C-LAMP Experiments
• 1000yr Spin-up + 200yr Control
• Experiment 1: Offline (Reanalysis driven)
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1.1 Spin up run
1.2 Control run (1798–2004)
1.3 Climate varying run (1948–2004)
1.4 Climate, CO2, and N deposition varying run (1798–2004)
1.5 Climate, CO2, N deposition varying run with land use change (1798–2004)
• Experiment 2: Coupled to CAM3
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2.1 Spin up run
2.2 Control run (1800–2004)
2.3 Climate varying run (1800–2004)
2.4 Climate, CO2, and N deposition varying run (1800–2004)
2.5 Climate, CO2, and N deposition varying run with land use change (1800–2004)
IPCC AR5 and Carbon
• Concentration driven (a la AR4)
o
No carbon feedback
• Emissions driven
o
o
Full carbon coupling
Radiation code does not see CO2
• Dynamic Vegetation coupling
• Land Use & Land Cover Change
Carbon Data – What, Where & When
• Storage
 Soil Carbon
 Biomass Fixing
• Flux Data:
 FluxNet
 Individual Investigators
 CO2 & CH4
Soil Carbon – Importance of Arctic
Batjes, 1996
New estimates
carbon inContent
frozen soils (NH)
Permafrost
OrganicofCarbon
Permafrost
zones
0-30 cm
0-100 cm
Continuous
110.38
298.75
25.5
67.44
Sporadic
26.36
63.13
Isolated Patches
29.05
67.10
191.29
496.42
Discontinuous
Total
Soil or deposit type
Soils 0–300 cm
C stocks
1024
Yedoma sediments
407
Deltaic deposits
241
Total
1672
Tarnocai et al 2009, GBC
Carbon (& other) Data Issues:
• All the usual problems
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Metadata
Continuity & Completeness
Quality Control
Different formats
Numerous data centers
Access
• Pro’s & Con’s of different data sets
• Errors: Representativeness & Instrumental
FluxNET
IPY AON Projects: Full annual cycle?
AON Towers: A tough environment!
Imnaviat
Cherskii
Photos: EEuskirchen@UAF
Arctic Specific Matters
1950
• Highest Q10 values are
in the Arctic
• Rapid change
• Shrub encroachment
already seen
• Huge carbon stocks
2002
0
1850
1900
2100
Current
Carbon
Emissions
Trajectory
of1950
Global2000
Fossil 2050
Fuel Emissions
CO2 Emissions (GtC y-1)
10
9
8
7
Actual emissions: CDIAC
Actual emissions: EIA
450ppm stabilisation
650ppm stabilisation
A1FI
A1B
(Avgs.)
A1T
A2
B1
B2
2007 2008
2006
2005
6
5
1990
1990
1995
1995
2000
2000
2005
2005
Raupach et al 2007, PNAS; Global Carbon Project 2009
2010
2010
THANKS
Community Land Model subgrid tiling structure
Gridcell
Landunit
Glacier
Columns
Wetland
Vegetated
Lake
Soil
Type 1
PFTs
Urban
Resolution
For IPCC AR5
2o and 0.5o
working towards 0.1o
Vegetation change (prescribed or prognostic)
Gridcell
Landunit
Glacier
Columns
Wetland
Vegetated
Lake
Soil
Type 1
PFTs
Urban
Dynamic global vegetation model (DGVM)
One Grid Cell In Canada
Mean Annual Temperature (2CO2)
Additional Temperature Change With Vegetation
Bonan et al. (2003) Global Change Biology 9:1543-1566
Bonan & Levis, unpublished
Carbon and Nitrogen cycling (CLM-CN)
Nitrogen cycle
Carbon cycle
Atm CO2
photosynthesis
Internal
(fast)
External
(slow)
denitrification
N deposition
Plant
assimilation
respiration
litterfall & mortality
3 C and 3 N litter pools
Litter / CWD
Soil Mineral
N
N fixation
decomposition
mineralization
3 C and 3 N soil pools
Soil Organic Matter
N leaching
Based on Biome-BGC, Thornton et al., 2009