CCSM Biogeochemistry WG Plans

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CCSM Biogeochemistry WG Plans

• CCSM1-carbon (Fung, Doney, Lindsay, John)
• Interactive land (CASA) and ocean (OCMIP) C
  cycles prognostic CO2 for atmospheric radiation
  
• Planned submission to IPCC 4th Assessment
• CCSM3-carbon (2 versions)
• Port CASA/OCMIP to CCSM3 physics (Fung,
  Doney, Lindsay, John, Murphy, SciDAC
  Collaboration)
• Land C-N coupling, disturbance (Thornton et
  al.)
• Ocn marine ecosystem dynamics (Moore et al.)
• Planned submission to IPCC 4th Assessment
• CCSM3-carbon
• Dust ? marine productivity ? C
• Land atmosphere coupling and active chemistry

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CCSM1-Carbon Inez Fung, Scott Doney, Jasmin
John, Keith Lindsay

• Modules
• Spin-up
• Results from Control
• Atm
• Land
• Ocean
• Fossil Fuel emission

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Modelers View of the Global C Cycle
FF
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COUPLING OF BIOGEOCHEMISTRY W BIOPHYSICS

• GPP from LSM
• dL/dt a_L NPP
• L/(t_bkgd t_cold-drought )
• All fluxes and pools updated 20 minutes

CASA
5
Iron-Carbon Biogeochemistry Model
Physical framework -NCOM global model (CCSM-ocean
1.4, x3 grid) -equilibrium solutions
(5-10kyr) Ocean Carbon Model Intercomparison
Project (OCMIP) -carbonate thermodynamics and
air-sea fluxes -prognostic biotic model
Enhancements -replace PO4 restoring w/
prognostic export flux -incorporate Fe
limitation and Fe cycling
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CCSM1-Carbon

• Modules
• Spin-up
• Results from Control
• Atm
• Land
• Ocean
• Fossil Fuel emission

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Spin-up Strategy

• Reminder Carbon inventory adjusts to climate
• Spin-up Goal find C distribution in eqm with
  the climate
• Challenge fickle models and climate
• Three flavors of CO2
• Tracers CO2 in atm
  CO2-tracer (x,y,z,t)
• (diagnostic of surface fluxes)
• 3 inert tracers net landocean net land net
  ocean
• Biogeochemistry CO2
  CO2-tracer (x,y,sfc, t)
• To drive fluxes into ocean
• Sensed by terrestrial photosynthesis
• Radiative CO2
  CO2-tracer (x,y,column, t)

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Coupling and Spin-up Strategy
CCSM 1.4 physics (with some changes) at T31/x3
CTracerprog CBGC280 CRad280
CTracerprog CBGCprog CRad280
CTracerprog CBGCprog CRadprog
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
c4.18 600 yr (03/25/04) start from y50 of
c4.17 280 ppm
c4.16 100 yr
c4.17 100 yr
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Coupled Carbon-Climate Model

• NCAR CCSM1 with interactive terrestrial and
  oceanic C cycles, Prognostic CO2(x,y,z,t)
• Control Run 600years
• Quantify climate effects on the carbon cycle
• No imposed trends (e.g. CO2 fertilization, N
  fertilization, land use modification...)
• Determine natural variability
• Background for CO2 sink detection
• FF Experiment specify FF emission since 1820

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CCSM1-Carbon

• Modules
• Spin-up
• Results from Control
• Atm
• Land
• Ocean
• Fossil Fuel emission

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Multi-Century Coupled Carbon/Climate Simulations
2.0
14.1
-2.0
13.6
Surface Temp.
Net CO2 Flux (Pg C/yr)
500
0
year

• Fully prognostic land/ocn BGC and
  carbon/radiation
• Atm-Land 70 PgC/yr ?? Atm-Ocean 90 PgC/yr ??
• Net Landocean 0?1 PgC/yr
• Stable carbon cycle and climate over 500y
• Projection of climate change on natural modes
• Detection attribution

?
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500 yr of Atm CO2 Variability

• Annual mean varies by 4ppm over 500years
• Surface 1.5 ppm higher than column average
• Column variability sfc variability

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Land and Ocean Contributions to Globally-averaged
Column CO2

• CO2_land more variable (6 ppm) than CO2_ocn
  (2.5 ppm)
• Conservation ? CO2_land and CO2_ocn have opposite
  trends
• Reduction of land flux ? lower atm CO2 ? greater
  oceanic outgassing
• But not always

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Time-evolving, 3-D Atmospheric CO2 fields
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CCSM1-Carbon

• Modules
• Spin-up
• Results from Control
• Atm
• Land
• Ocean
• Fossil Fuel emission

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Annual Net Atm-Land Flux Net Ecosystem
Production Rh (70 PgC/y ?) NPP (70 PgC/y
?)
Natural NEP Variability ? noise for detecting
anthropogenic land sink
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Terrestrial Carbon Inventory
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Variability Mechanism e.g. Wood

• NPP responds to instantaneous climate
• t_wood fixed 20 yrs
• t_cwd 15y f(soilT) g(soil_moisture)
• CWD integrates over decadal climate variability

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CCSM1-Carbon

• Modules
• Spin-up
• Results from Control
• Atm
• Land
• Ocean
• Fossil Fuel emission

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Ocean Carbon Cycle Variability
0.35
Air-sea CO2 Flux (Pg C/yr)
9.25
8.8
-0.25
Export Flux
500
0
year
-global interannual variability in CO2 flux of
/-0.3 Pg Cyr -weak Equatorial Pacific
variability (biases in base state)
Fung, Doney, Lindsay John
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Long-term Ocean Drift
Global Salinity (PSS)
170
z
ACC Transport
146
0
500
year
year
-Most properties relatively stable over 0-500
years -Drift in Antarctic Circumpolar Current and
salinity vertical redistribution (w/
corresponding drift in DIC and Alkalinity
concentrations)
Fung, Doney, Lindsay John
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Ocean Variability Mechanisms
Particle export
Fresh- water
mol C/m2
-Maps of annual rms (y 0-200 C4.18) -Regions of
high variability in North Atlantic Pacific,
tropics and Southern Ocean -Mechanisms differ
across regions
Fung, Doney, Lindsay John
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CCSM1-Carbon

• Modules
• Spin-up
• Results from Control
• Atm
• Land
• Ocean
• Fossil Fuel emission

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CCSM1-carbon Control and Fossil Fuel Expts
Control (c4.18)
400 yr
1000 yr
100 yr
1) Prescribed CO2 Emissions
CO2/Radiation Coupling
c4.19
Run ensembles when feasible
2) Prescribed CO2 Emissions No
CO2/Radiation Coupling
3) Prescribed CO2 Concentrations
CO2/Radiation Coupling
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Prescribed Fossil Fuel Experiment (C4.19)
40 Pg C uptake
320
80 Pg C build-up
Ocean
285
Net Atm. CO2
1960
1820
year
-1/3 of fossil fuel emissions taken up by
ocean -small temperature rise (0.25 K) -land
release only somewhat larger than variability in
control (6 Pg C)
8 Pg C release
Land
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CCSM Carbon-Climate GCMs for IPCC 2007
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Land, Atmosphere and Ocean Inventories
2.0
283.5
-2.0
Land
278.5
Net CO2 Flux (Pg C/yr)
Ocean
Fung, Doney, Lindsay John
500
0
year
-Approximately stable atmosphere CO2
concentration -Substantial variability on
interannual, decadal and centennial
time-scales -Redistributions from land to
atmosphere as large as 10 Pg C
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Marine BGC Module

• OCMIP Biotic Model
• prognostic export production
• iron limitation and cycling

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Globally Averaged Net Surface Fluxes (land /- 70
PgC/yr ocean /- 90 Pg/yr)

• Stable !!! Over 500 years of integration
• Large interannual and interdecadal variability
  (1) in landocean surface fluxes
• Natural flux variability contemporary carbon
  sink

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Land BGC Module
CO2
H2O
Energy
LAI

• Based on coupling of CASA BGC Land
  Biogeophysics
• dynamic allocation
• prognostic LAI and phenolgy

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Multi-Century Coupled Carbon/Climate Simulations
1.5
14.1
-1.5
13.6
Surface Temp.
Net CO2 Flux (Pg C/yr)
0
200
year
Fung, Doney, Lindsay John
-Fully prognostic land/ocn BGC and
carbon/radiation -Stable carbon cycle and
climate over 200y -Projection of climate change
on natural modes -Detection attribution
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Variability Mechanisms Modes
Particle export
30
10
Air-sea flux
3
Fresh- water
1
Fung, Doney, Lindsay John
35
Carbon/Climate Control Simulation (100y)
1.0
14.1
-1.0
Net CO2 Flux
13.7
284
Surface Temp.
283
Stable carbon cycle and climate over O(100y)
with fully prognostic land/ocn BGC and
carbon/radiation coupling
282
Surface Atm. CO2