The Potential Role of NCAR in the Future Carbon Observing Network Britton B. Stephens Atmospheric Technology Division, Research Aviation Facility

Necessity of and challenges to measuring regional carbon fluxes Nature of the problem –Why does the observing network need to be expanded? –What amount of support can be expected? Determining the best approach –Variability in fluxes and concentration fields –Modeling and network design studies NCAR’s potential role –New technologies for autonomous instrumentation –Coordination of large-scale measurement programs –Ecological, transport, and data-assimilation modeling

Expected from fossil fuel emissions Annual-mean CO 2 Exchange (GtCyr -1 )

IPCC, 2001 Stabilization Scenarios “…human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future. Within a few centuries we are returning to the atmosphere and oceans the concentrated organic carbon stored in sedimentary rocks over hundreds of millions of years.” Roger Revelle and Hans Suess, 1957 Motivations Academic Climatic Political Economic “The United States [will] help lead the way by advancing the science on climate change, advancing the technology to monitor and reduce greenhouse gases....” President George W. Bush, June, 2001 Kyoto Protocol Article 3.3 The net changes in greenhouse gas emissions from sources and removals by sinks resulting from direct human-induced land-use change and forestry activities... shall be used to meet the commitments.... Article 6.1 For the purpose of meeting its commitments under Article 3, any Party included in Annex I may transfer to, or acquire from, any other such Party emission reduction units....

Predicted gradients due to fossil fuel emissions alone } Observations (from TransCom 1, Law et al., 1996) Modeled and Observed Meridional CO 2 Gradients

(From TransCom 3, Gurney et al., 2002)

Continental-scale Inversion Results StudyTime Period North American Uptake Eurasian Uptake Fan et al., ± 0.5 GtCyr ± 0.6 GtCyr -1 Bousquet et al., ± 0.7 GtCyr ± 1.0 GtCyr -1 Gurney et al., ± 0.6 GtCyr ± 0.9 GtCyr -1

Need not only more measurements, but also better models

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

Relevant Planning Documents (Current U.S. carbon cycle expenditures $40-50M/yr) CCSP, 1999: +$ M $ M/yr NACP, 2002: +$40-70M/yr $ M/yr LSCOP, 2002: $250M $150M A U.S. Large-scale CO 2 Observing Plan - Oceans and Atmosphere NOAA - OGP

(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,

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

(LSCOP, 2002)

TURC/NDVI Biosphere, Takahashi Ocean, EDGAR Fossil Fuel (Ute Karstens and Martin Heimann, 2001)

Much information in short-term variations (Rachel Law, submitted to Tellus, 2001) For Australian region and 4 observing stations, even biased high-frequency measurements do better than long-term means

Continental Observing Technologies LiCor, Inc. Analyzer 0.1 ppm, ~$50K Atmospheric Observing Systems 0.1 ppm, ~$20K NOAA SBIR Under Development RMT, Ltd. Sensor 0.5 ppm, ~$2K Automated Flask Sampling 0.1 ppm, ~$20K NOAA/CMDL

Continental Observing Technologies Upward-looking Fourier-transform infrared (FTIR) spectrometers Active and passive satellite CO 2 measurements ~ 1-3 ppm in column average

Relevant NCAR Expertise Field measurements of atmospheric trace gases (ATD, ACD) Autonomous instrumentation networks (ATD) Atmospheric transport and ecological modeling (MMM, CGD) Data assimilation and dataset management (ACD, CGD, SCD) Industrial emissions and land-use characterization (ESIG, CGD) FTIR measurements and satellite planning (ACD, CGD) Biogeosciences Initiative (all divisions) Inexpensive and robust CO 2 sensors Data assimilation tools FTIR measurements Long range: CO 2 sondes Potential Applications

Niwot Ridge Pilot Study August 2002 Jeilun Sun, Steve Oncley, Alex Guenther, Dave Schimel, Don Lenschow, Britt Stephens, Russ Monson, and others.

Prototype Inexpensive/Autonomous CO 2 System - RMT Sensor - Aluminum LPG cylinders - Goals: 1-2 year service schedule Total installation ~ $2000

Towers over 650 feet AGL

Model Data Integration and Network Design for Biogeochemical Research (CDAS) Boulder Colorado, USA May 20 – 31, 2002 Hosted by NCAR & Colorado State University David Schimel and Britton Stephens, co-chairs An advanced study institute designed to teach and develop assimilation tools and design networks to measure regional carbon cycle sources and sinks.

NCAR CarboNet?

Conclusions Present observing network and modeling tools are inadequate to measure continental fluxes We need information on regional scales Interest and support are likely to increase NCAR scientists will play a major role in developing the future carbon observing network