ESRL Integrating Research and Technology Themes

Carbon Cycle Science

  1. Goal and Scope
  2. The scientific goal is to quantify and understand the dynamics of sources and sinks of atmospheric carbon, to improve scenarios of long-term climate forcing by CO2 and CH4, and to provide decision-support information aimed at controlling their atmospheric burdens.

    The present scope includes:

    • Sustained, global, high-accuracy measurements of atmospheric CO2 and CH4 and their isotopic ratios (both continuous and discrete grab samples).
    • A network of sustained small aircraft and tall tower measurements of CO2 and CH4 in North America (primarily the U.S.), as part of the North American Carbon Program.
    • Inverse modeling with chemical atmospheric transport models to translate observed concentration patterns into time-dependent source/sink patterns, globally and regionally.
    • Studies of patterns of climate variability affecting the carbon dioxide growth rate.
    Future needs include:
    • Developing new inverse models, which require advanced computer techniques.
    • Developing robust and low-maintenance instrumentation for gas measurement.
    • Developing products for stakeholder groups, for example in the scientific, energy production, and carbon sequestration areas.

  3. Rationale and Payoff
  4. Projecting climate into the future critically depends on how well we can understand the exchange of carbon dioxide between the atmosphere on the one hand and the oceans and terrestrial biosphere on the other. NOAA has taken on the challenge outlined in the U.S. Carbon Cycle Science Plan (1999) and the North American Carbon Program Implementation Plan (2004) to provide the atmospheric measurements and analyses required to reduce the uncertainty in the magnitude of the amount of carbon dioxide taken up by North America and to determine regional carbon fluxes.

    The NOAA global flask air sampling network and NOAA's Globalview CO2 and CH4 data bases, which include contributions from other countries, will continue to provide the main data source for Intergovernmental Panel on Climate Change (IPCC) assessments of climate change. Isotopic analyses of CO2 and CH4 distinguish between different source processes. Currently CO, H2, N2O, and SF6 are also measured for all flask samples. In development are 14CO2, COS and a suite of VOCs (including non-methane hydrocarbons of natural origin) and halocompounds. The additional species provide characterizations of air mass origins to allow better attribution of CO2 variance to specific source/sink processes, while they have an obvious application to air quality. Tropospheric ozone will be measured on the flights carried out with charter aircraft, providing an additional cross-cut with the Air Quality program.

  5. Major Collaborators and Their Research Foci
    1. Earth System Research Laboratory
      • Global Monitoring Division: Surface, aircraft and tall tower measurements of carbon gases and tracers. Inverse atmospheric chemical transport models. Input to CCSP Synthesis Assessment Reports and "State of the Carbon Cycle Reports", for example chapter lead author. Estimates of North American carbon uptake and global carbon sources and sinks. Similar input to IPCC reports.
      • Chemical Sciences Division: Chemistry relevant to air quality and source attribution, instrument development, leadership in IPCC Assessments which use results of NOAA’s Carbon Cycle Science program.
      • Physical Sciences Division: Climate variability studies that focus on events and trends that might affect the global carbon dioxide growth rate.
      • Global Systems Division: Carbon and water cycle coupling through photosynthesis and evapotranspiration. Application of the Rapid Update Cycle (RUC) model for inverse transport model source-sink analyses with the much higher density of carbon dioxide data available in the U.S. through the North American Carbon Program.
    2. Other NOAA
      • Atlantic Oceanographic and Meteorological Lab: Ocean carbon inventory and pCO2 measurements, modeling work with partners.
      • Geophysical Fluid Dynamics Lab: Carbon cycle models, carbon in global climate models.
      • Pacific Marine Environmental Lab: Ocean carbon inventory and pCO2 measurements, modeling work with partners.
      • NESDIS/ORA: Satellite measurements of carbon gases.
      • NESDIS/NGDC: Global maps of biomass burning, gas flares, and human settlements - for modeling the spatial and temporal distribution of carbon emissions.
    3. Others
      • Institute for Arctic Alpine Research: Isotopic analyses, 14CO2, hydrocarbon analyses
      • CIRES: Fully integrated contributions to all aspects of the program.
      • Interagency partners in the North American Carbon Program: DOE (ecosystem flux measurements), NASA (airborne field studies), NSF (process studies), USDA (land management, forest service inventories), USGS (rivers, reservoirs), Canadian agencies.
  6. Contributions to NOAA Goals
    • NOAA Strategic Plan: Performance Measure - "Reduce the uncertainty in the magnitude of the North American carbon uptake" (also a GPRA measure).
    • NOAA Climate Goal (Program): CCSP Synthesis Assessment Product - "North American carbon budget and implications for the global carbon cycle."
    • OAR Strategic Plan FY05-10: Performance Measure - "By 2008, reduce the uncertainty in the magnitude of the amount of carbon taken up by U.S. contiguous land area."
  7. Major Information Products, Customers, and Linkages
    • "State of the Carbon Cycle Reports" (SOCCR): The first SOCCR will focus on North American carbon uptake and will represent the CCSP Synthesis Assessment product 2.2 due October 2005. Stakeholder involvement is planned from the very beginning.
    • Data, analysis, leadership and authorship for IPCC Assessments.
    • Decision support for carbon management such as the CCTP sequestration program.