1. CCSM Biogeochemistry WG Plans
CCSM1-carbon
Interactive land (CASA’) and ocean (OCMIP’) C cycles; prognostic CO2 for atmospheric radiation
Planned submission to IPCC 4th Assessment
CCSM3-carbon
Port CASA’/OCMIP’ to CCSM3 physics
Thornton’s new land model (C-N coupling, disturbance)
More advanced ocean (marine ecosystem dynamics)
CCSM3-carbon+
Dust  marine productivity  C
Land atmosphere coupling and active chemistry

2. Predicting Co-evolution of CO2 and Climate
Atmosphere
CO2 = 280 ppmv (560 PgC) + …
Ocean Circ.
+ BGC
Biophysics
37400 Pg C
2000 Pg C
90±
60±
Turnover
Time of C yr
time of C
101 yr
Fossil Fuel
~6 PgC/yr

3. } Land BGC Module CO2 NPP R_h GPP R_a H2O Energy LAI
Sfc
Metab
Soil
Struc
Coarse
Wdy Debris
Microb
Slow
Passive
NPP
R_h
Leaf
Root
Wood
GPP
R_a
allocation
H2O
Energy
LAI
Based on coupling of CASA BGC & Land Biogeophysics
dynamic allocation
prognostic LAI and phenolgy

4. Marine BGC Module OCMIP Biotic Model + prognostic export production
iron limitation and cycling

5. Coupling and Spin-up Strategy
CCSM 1.4 physics (with some changes) at T31/x3
CTracer=prog
CBGC=280
CRad=280
CTracer=prog
CBGC=prog
CRad=280
CTracer=prog
CBGC=prog
CRad=prog
land BGC spin-up
active land/atm
clim. or coupled model SSTs
O(102)y
coupled physics
land/ocn BGC adjustment
coupled physics
land/ocn/atm BGC adjustment
coupled physics
fully coupled carbon-climate
ocean BGC spin-up
active ocean
O(103)y
c4.11
100 yr
c4.14
50 yr
c4.15
~100 yr (11/5/03)
start from y=25 of c4.14
280 ppm

6. Carbon/Climate Control Simulation (~100y)
+1.0
14.1
-1.0
Net CO2 Flux
13.7
Surface Temp.
284
283
“Stable” carbon cycle and climate over O(100y) with fully prognostic land/ocn BGC and carbon/radiation coupling
282
Surface Atm. CO2

7. Time-evolving, 3-D Atmospheric CO2 fields

8. CCSM1-carbon Control and Fossil Fuel Experiments
Control (c4.15)
300 yr
1000 yr
1) Prescribed CO2 Emissions
CO2/Radiation Coupling
Run ensembles when feasible
2) Prescribed CO2 Emissions
No CO2/Radiation Coupling
3) Prescribed CO2 Concentrations
CO2/Radiation Coupling

9. CCSM Carbon-Climate GCM’s for IPCC 2007
CASA’
OCMIP’+Fe
NCAR Origin
(LANL)
Doney, Fung, John, Lindsay
CCSM 3.?
IBM SP’s
NCAR (ORNL, NERSC)
Fung, Doney, John, Lindsay, Wehner, others?
CLM3
Ocean Eco
Thornton, Mahowald, Lindsay, Moore, Fung, Doney

10. New Land BGC model -Nitrogen/Carbon Coupling -Disturbance N-limited
NEE response to +1° C step change (decid broadleaf)
N-limited
Illustration of the influence of nitrogen cycle dynamics on the carbon cycle response to forced climate variation. The same model has been run with (solid line) and without (dashed line) nitrogen cycle dynamics. Results shown for a single grid cell in the temperate deciduous broadleaf forest region of eastern U.S. summary: N cycle dynamics change both the sign and the time constant for sensitivity of terrestrial NEE to temperature.
non N-limited

11. Model GPP, Conterminous U.S.
18-year mean from coupled carbon-nitrogen cycle model
Summary: We are developing global and high-resolution regional modeling frameworks in parallel, to improve our ability to address science questions at policy-relevant spatial and temporal scales.

12. New Marine Ecosystem Model
Physical Framework
-global POP-CCSM 2.0 (x3 grid)
-multi-decade solutions
OCMIP-Fe BGC Model
-ballast-model particle sinking and remineralization
-Fe scavenging as function of particle flux
-coastal sediment Fe source
Multi-element, multi-functional group (Moore et al. 2002)
-fixed C/N/P elemental ratios (21 vs. 46 tracers)
-variable Fe/C & Si/C
Moore, Doney & Lindsay (in prep.)

13. Future/ongoing work Upper Ocean Ecosystem Model
-global seasonal evaluation
(draft manuscript)
-historical and JGOFS time-series/process study sites
-interannual variability (climate & dust flux)
Eco-BGC Coupling
-quasi-equilibrium solutions (w/ LANL)
-particle flux/ballast model
-sediments (w/ U. Chicago)

14. A less dusty future? Mahowald and Luo, 2003
Simulations using CSM 1for the first time make estimates of future dust emissions. Use 6 different scenarios
Estimates suggest 20-60% lower emissions/deposition in the future (sensitive to model).
Estimates in pre-industrial sensitive to case (ice core data does not constrain).
Important implications:
‘natural’ aerosols such as mineral aerosols are HIGHLY sensitive to human activities.
Important impacts on climate and ocean uptake of CO2 suggest significant feedbacks due to ‘natural’ aerosol changes

15. Future Natural Aerosol Work
Online coupled simulations with other aerosols
Online coupled simulations with ocean biogeochemistry
Plans to include sea salts and ‘natural’ biomass burning aerosol impacts
Paleoclimate simulations to test model sensitivity and important feedbacks

16. N forcing
Summary for Policymakers, IPCC 2001

17. Putting the pieces together:
The GLOBAL C CYCLE
The GLOBAL N CYCLE

19. Summary: Including new sunlit vs
Summary: Including new sunlit vs. shaded canopy integration increases global GPP by 50%. Including realistic treatment of specific leaf area increases global GPP by an additional 15%. Global target value is around 120 PgC/yr.

20. Harvest loss: gC m-2
Summary: Continuing to quantify the dominant factors affecting net terrestrial carbon exchange on decadal and longer timescales. Shown here are the relative effects of a 50% harvest, a 1 degree C temperature increase, an 80 ppmv increase in CO2, and a doubling of atmospheric N deposition, at Duke Forest. Top plots shown without harvest to resolve dynamics in the other factors. Bottom plots show that harvest dominates the other factors across timescales.

21. What are the implications of N deposition
for the global carbon cycle with a simple perturbation approach?
from Holland et al 1997, JGR Atmospheres 102:15,849-15,866).