1. Regional CO 2 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 Andrews Anna Michalak Maarten Krol Jeff Whitaker Wouter Peters Lori Bruhwiler John B. Miller Pieter Tans Adam Hirsch Kevin Schaefer Arlyn Andrews Anna Michalak Maarten Krol Jeff Whitaker NOAA- CMDL ICDC7-September 27th-2005

2. Motivation Many new (continuous) CO 2 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 CO 2 observations to surface processes The framework should include high detail of spatial and temporal variability

3. Fire Flux Module SEAT-A Observations Biosphere Flux Module Fossil Fuel Flux Module Ocean Flux Module Insights...? System for Ensemble Assimilation of Tracers in the Atmosphere ICDC7 Sept 2005 TM5 atmospheric transport model + Ensemble Kalman Filter

4. Fires SEAT-A Observations Biosphere Fossil Fuels Oceans FireModule Biosphere Module Fossil Fuel Module Ocean Module System for Ensemble Assimilation of Tracers in the Atmosphere Insights...? Peters, W., J.B. Miller, J. Whitaker, A.S. Denning, A. Hirsch, M.C. Krol, D. Zupanski, L. Bruhwiler, and P.P. Tans, An ensemble data assimilation system to estimate CO 2 surface fluxes from atmospheric trace gas observations, J. Geophys. Res., submitted, 2005.

5. Flux Modules Simple parameterizations of flux behavior (for now...) Include carbon cycle ‘auxiliary’ information Fill in details we cannot see from atm. CO 2..., weather, NDVI, pCO 2, biosphere maps, fire counts, chlorophyl,... Straightforward extension to more tracers, isotopes optimizable parameters to constrain net flux Diagnosing parameters can inform on modules ICDC7 Sept 2005

6. clim. pCO 2 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 pCO 2 in air (Kettle & Merchant, 2005) TM5 daily sea ice mask 11 scalar multipliers for TransCom region net fluxes Ocean Module Ocean Module ICDC7 Sept 2005

7. 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=Q 10 relationship with 2 meter temperature R scaled to match NEP 1ºx1º spatial, 3-hourly temporal T 2m 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 Module ICDC7 Sept 2005

8. Fluxes for June 2004 no data assimilation Daily averages ocean: dark is uptake, light is emission Land: green is uptake, red is emission ICDC7 Sept 2005

9. D.A. Biosphere Biosphere Module OceanModule 50-100 obs/week Time ICDC7 Sept 2005 TM5 +Ensemble Kalman Filter 146 parameters/wee k

10. Insights Preliminary 2001 Annual Mean biosphere fluxes in µmol/m 2 /s (52x) 24 parameters! (52x) 111+11 parameters! + + - - + - -0.59± 0.56 PgC/yr ICDC7 Sept 2005

11. Conclusions CMDL has a working CO 2 data assimilation framework Allows many observations, many unknowns Auxiliary information included through flux modules Short-term improvements: more sophisticated modules more CO 2 observations Covariances and model-data mismatch First flux estimates for validation in progress ICDC7 Sept 2005

12. TransCom aggregation ICDC7 Sept 2005

13. 0.75 0.0 0.075 0.75 0.00.075 Prior land =±0.75 Prior ocean=±0.10

14. Seasonal Cycle North America Temperate 10 0 -15 2000.0 2002.5 PgC/yr