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 Coupled Atmo-Ocean-Land + Carbon GCMs o Numerous carbon pools in models o Generally fixed Q10 values (global) o No nitrogen cycle included Simulations with & without interactive CO 2 Later found that Nitrogen limitation would decrease carbon uptake

C4MIP - Results No consensus on total NPP response to Climate Change o ↑T + ↑CO 2 → ? o Will the land be a sink or source? Carbon uptake ability decreases o ↑T → ↓CO 2 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)  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  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 Full carbon coupling o Radiation code does not see CO 2 Dynamic Vegetation coupling Land Use & Land Cover Change

Carbon Data – What, Where & When Storage  Soil Carbon  Biomass Fixing Flux Data:  FluxNet  Individual Investigators  CO 2 & CH 4

Soil Carbon – Importance of Arctic Batjes, 1996

Tarnocai et al 2009, GBC Soil or deposit typeC stocks Soils 0–300 cm1024 Yedoma sediments 407 Deltaic deposits 241 Total 1672 Permafrost zones 0-30 cm0-100 cm Continuous Discontinuous Sporadic Isolated Patches Total New estimates of carbon in frozen soils (NH) Permafrost Organic Carbon Content

Carbon (& other) Data Issues: All the usual problems  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! Cherskii Imnaviat Photos:

Arctic Specific Matters Highest Q10 values are in the Arctic Rapid change Shrub encroachment already seen Huge carbon stocks

Raupach et al 2007, PNAS; Global Carbon Project 2009 (Avgs.) Trajectory of Global Fossil Fuel Emissions Current Carbon Emissions

THANKS

Community Land Model subgrid tiling structure Gridcell GlacierWetlandLake Landunit Columns PFTs UrbanVegetated Soil Type 1 Resolution For IPCC AR5 2 o and 0.5 o working towards 0.1 o

Gridcell GlacierWetlandLake Landunit Columns PFTs UrbanVegetated Soil Type 1 Vegetation change (prescribed or prognostic)

Dynamic global vegetation model (DGVM) One Grid Cell In Canada Bonan et al. (2003) Global Change Biology 9: Bonan & Levis, unpublished Mean Annual Temperature (2  CO 2 ) Additional Temperature Change With Vegetation

decomposition litterfall & mortality Atm CO 2 Plant Litter / CWD Soil Organic Matter Carbon cycle respiration Soil Mineral N N deposition N fixation denitrification N leaching Nitrogen cycle Internal (fast) External (slow) mineralization assimilation photosynthesis Carbon and Nitrogen cycling (CLM-CN) Based on Biome-BGC, Thornton et al., C and 3 N litter pools 3 C and 3 N soil pools