Regional CO2 Flux Estimates for North America
through data assimilation of NOAA CMDL trace gas observations
Wouter Peters Lori Bruhwiler John B. Miller Pieter Tans
Adam Hirsch Kevin Schaefer Arlyn AndrewsAnna Michalak Maarten KrolJeff Whitaker
Wouter Peters Lori Bruhwiler John B. Miller Pieter Tans
Adam Hirsch Kevin Schaefer Arlyn AndrewsAnna Michalak Maarten KrolJeff Whitaker
NOAA- CMDL
ICDC7-September 27th-2005
MotivationMany new (continuous) CO2 observations from North America are coming in over the next few years
From these, we want to study carbon cycle behavior
This requires a framework that efficiently links atmospheric CO2 observations to surface processes
The framework should include high detail of spatial and temporal variability
Fire Flux Fire Flux ModuleModule
SEAT-A
ObservatioObservationsns
Biosphere Biosphere Flux Flux
ModuleModule
Fossil Fuel Fossil Fuel FluxFlux
ModuleModule
Ocean Flux Ocean Flux ModuleModule
Insights...?
System forEnsembleAssimilation ofTracers in theAtmosphere
ICDC7Sept 2005
TM5 atmospheric transport TM5 atmospheric transport model + Ensemblemodel + Ensemble
Kalman FilterKalman Filter
FiresFires
SEAT-A
ObservatioObservationsns
BiosphereBiosphere
Fossil FuelsFossil Fuels
OceansOceans
Fire Fire ModuleModule
Biosphere Biosphere ModuleModule
Fossil FuelFossil FuelModuleModule
Ocean Ocean ModuleModule
System forEnsembleAssimilation ofTracers in theAtmosphere
Insights...?Peters, W., J.B. Miller, J. Whitaker, A.S. Denning, A. Hirsch, M.C. Krol, Peters, W., J.B. Miller, J. Whitaker, A.S. Denning, A. Hirsch, M.C. Krol, D. Zupanski, L. Bruhwiler, and P.P. TansD. Zupanski, L. Bruhwiler, and P.P. Tans, An ensemble data assimilation , An ensemble data assimilation
system to estimate COsystem to estimate CO22 surface fluxes from atmospheric trace gas surface fluxes from atmospheric trace gas observations, observations, J. Geophys. Res.J. Geophys. Res., , submittedsubmitted, 2005., 2005.
Flux Modules
Simple parameterizations of flux behavior (for now...)
Include carbon cycle ‘auxiliary’ information
Fill in details we cannot see from atm. CO2
..., weather, NDVI, pCO2, biosphere maps, fire counts, chlorophyl, ...
Straightforward extension to more tracers, isotopes
optimizable parameters to constrain net flux
Diagnosing parameters can inform on modulesICDC7Sept 2005
clim. pCO2 in sea water (Takahashi, 2002)
Clim. SST and salinity for saturation vapor pressure, solubility, gas transfer
TM5 3-hourly winds for quadratic gas transfer
TM5 3-hourly surface pressure to scale pCO2 in air (Kettle & Merchant, 2005)
TM5 daily sea ice mask
11 scalar multipliers for TransCom region net fluxes
Ocean Module
Ocean Ocean ModuleModule
ICDC7Sept 2005
soon: VPRM by Wofsy, Pathmathevan, Matross
Now: similar to Olsen and Randerson, 2004
monthly mean CASA NEP (neutral biosphere)
GPP=2*NPP distributed with solar radiation
R=Q10 relationship with 2 meter temperature
R scaled to match NEP
1ºx1º spatial, 3-hourly temporal T2m and radiation (TM5 ->ECMWF)
11 Transcom land regions subdivided into 19 possible biome types (Olson v1.3)
135 ‘biome regions’ with each one scalar to be optimized
Scalar multiplies the net-flux
Biosphere Module
Biosphere Biosphere ModuleModule
ICDC7Sept 2005
Fluxes for June 2004no data assimilation
Daily averagesocean: dark is uptake, light is emissionLand: green is uptake, red is emissionICDC7
Sept 2005
D.A.
BiosphereBiosphereBiospherBiosphere Modulee Module
Ocean Ocean ModuleModule
50-100 obs/week
TimeICDC7
Sept 2005
TM5 TM5 +Ensemble+Ensemble
Kalman FilterKalman Filter
146 146 parameters/wparameters/w
eekeek
Insights
Preliminary 2001 Annual Mean biosphere fluxes in
µmol/m2/s
(52x) 24 (52x) 24 parameters!parameters!
(52x) 111+11 (52x) 111+11 parameters!parameters!
++
--
+-
-0.59± 0.56 -0.59± 0.56 PgC/yrPgC/yr
ICDC7Sept 2005
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Conclusions
CMDL has a working CO2 data assimilation framework
Allows many observations, many unknowns
Auxiliary information included through flux modules
Short-term improvements:
more sophisticated modules
more CO2 observations
Covariances and model-data mismatch
First flux estimates for validation in progressICDC7
Sept 2005
Seasonal CycleNorth America Temperate
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
10
0
-152000.0 2002.5
PgC/yr