1. Model-data Integration and Network Design for Biogeochemical Research (CDAS) May 20 – 31, 2002 Hosted by NCAR & Colorado State University

2. Overriding Themes in Carbon Cycle Research Motivations for constraints on regional (~1000 km) scales are many and growing Challenges to determining regional CO 2 fluxes involve both data and modeling Integrated approach needed to move forward - data assimilation, network design

3. Regional scale is critical for linking to underlying processes (NRCS/USDA, 1997) (SeaWIFS, 2002) CHLOROPHYLL TEMPERATURE (C) (IPCC, 2001)

4. Relevant U.S. Planning Documents (Current U.S. carbon cycle expenditures $40-50M/yr) CCSP, 1999: +$135-300M 2000-2005 $200-250M/yr 2005- NACP, 2002: +$40-70M/yr 2002-2005 +$50- 100M/yr 2005- LSCOP, 2002: $250M 2002-2006 $150M 2007-2011

5. (from The Emerging International Greenhouse Gas Market, Pew Center on Global Climate Change, 2002) At $2 per ton CO 2 e: 0.1 GtC (~1/10 of current uncertainty on U.S. uptake and ~1/4 of current U.S. emissions above Kyoto obligation) would trade at approximately... $700,000,000. 00

6. Continental Signal Versus Noise Using Current Inverse Methodologies (TransCom, 2002)

7. Unresolved variance presently contains most of the information on continental-scale fluxes

8. (LSCOP, 2002)

9. Many network design studies 1 have been conducted, with similar results: Need more data - continental, (South America, Africa, Siberia) - Southern Ocean - airborne 1 e.g. Rayner et al., 1996; Gloor et al., 1999; LSCOP, 2002; Patra, subm. 2001; Suntharalingam, subm. 2002

10. CDAS Approach Bring together observationalists and modelers to form an integrated approach to improving our understanding of the global carbon cycle. Initial effort: Network design exercises based on a selected assimilation modeling strategy. Ongoing: Further development of the assimilation tool and support for testing and planning/educational use by the community.

11. Technical Team Roger Dargaville (CGD) David Baker (ASP) Steve Aulenbach (CGD) Jennifer Oxelson (ESIG/ATD) Kathy Fisher (CGD) Dave Brown (SCD) Mark Moore (SGD)