The Need for Atmospheric Carbon Dioxide Measurements from Space: Contributions from a Rapid Reflight of the Orbiting Carbon Observatory May 12, 2009 Contributors: Stacey Boland, Jet Propulsion Laboratory, California Institute of Technology, USA Hartmut Bösch, University of Leicester, U.K. Linda Brown, Jet Propulsion Laboratory, California Institute of Technology, USA John Burrows, University of Bremen, Inst. of Environmental physics, Germany Philippe Ciais, Laboratoire des Sciences du Climat et de l’Environnement/IPSL, France Brian Connor, BC Consulting, , USA David Crisp, Jet Propulsion Laboratory, California Institute of Technology, USA Scott Denning, Colorado State University, USA Scott Doney, Woods Hole Oceanographic Institution, USA Richard Engelen, European Centre for Medium Range Weather Forecasts, U.K. Inez Fung, University of California Berkeley, USA Peter Griffith, NASA Goddard Space Flight Center, USA Daniel Jacob, Harvard University, USA Ben Johnson, University of Maryland, USA Javier Martin-Torres, Jet Propulsion Laboratory, California Institute of Technology, USA Anna Michalak, University of Michigan, USA Charles Miller, Jet Propulsion Laboratory, California Institute of Technology, USA Denis O’Brien, Colorado State University, USA Igor Polonsky, Colorado State University, USA Christopher Potter, NASA Ames Research Center, USA James Randerson, University of California, Irvine, USA Peter Rayner, Laboratoire des Sciences du Climat et de l’Environnement/IPSL, France Ross Salawitch, University of Maryland, USA Michelle Santee, Jet Propulsion Laboratory, California Institute of Technology, USA Pieter Tans, National Oceanic and Atmospheric Administration, USA Paul Wennberg, California Institute of Technology, USA Debra Wunch, California Institute of Technology, USA Steven Wofsy, Harvard University, USA Yuk Yung, California Institute of Technology, USA i OCO Science Team Principal Investigator: David Crisp, NASA Jet Propulsion Laboratory, Pasadena, CA, USA Deputy Principal Investigator: Charles Miller, NASA Jet Propulsion Laboratory, Pasadena, CA, USA Science Team: Francois-Marie Breon, Laboratoire des Sciences du Climat et l'Environnement, France Hartmut Boesch, University of Leicester, Leicester, U.K. Amy Braverman, Jet Propulsion Laboratory, Pasadena, CA, USA Linda Brown, NASA Jet Propulsion Laboratory, Pasadena, CA, USA Carol Bruegge, NASA Jet Propulsion Laboratory, Pasadena, CA, USA John Burrows, University of Bremen, Inst. of Environmental Physics, Bremen, Germany Frederic Chevallier, Laboratoire des Sciences du Climat et l'Environnement, France Philippe Ciais, Laboratoire des Sciences du Climat et l'Environnement, France Brian Connor, BC Consulting, Lauder, New Zealand Scott Doney, Woods Hole Oceanographic Institution, Woods Hole, MA, USA Richard Engelen, European Centre for Medium Range Weather Forecasts, U.K. Inez Fung, University of California, Berkeley, CA, USA David Griffith, University of Wollongong, New South Wales, Australia Daniel Jacob, Harvard University, Cambridge, MA, USA Anna Michalak, University of Michigan, Ann Arbor, MI, USA Vijay Natraj, California Institute of Technology, Pasadena, CA, USA Justis Notholt, University of Bremen, Inst. of Environmental Physics, Bremen, Germany Denis O'Brien, Colorado State University, Fort Collins, USA Christopher O'Dell, Colorado State University, Fort Collins, CO, USA Paul Palmer, Leeds University, U.K. University of Edinburgh, U.K. Steven Pawson, GMAO / NASA Goddard Space Flight Center, Greenbelt, MD, USA Randy Pollock, NASA Jet Propulsion Laboratory, Pasadena, CA, USA Igor Polonsky, Colorado State University, Fort Collins, CO, USA James Randerson, University of California, Irvine, CA, USA Peter Rayner, Laboratoire des Sciences du Climat et l'Environnement, France Matt Rogers, Colorado State University, Fort Collins, CO, USA Ross Salawitch, University of Maryland, College Park, MD, USA Stan Sander, NASA Jet Propulsion Laboratory, Pasadena, CA, USA Graeme Stephens, Colorado State University, Fort Collins, CO, USA Pieter Tans, National Oceanic and Atmospheric Administration, Boulder, CO, USA Geoffrey Toon, NASA Jet Propulsion Laboratory, Pasadena, CA, USA Paul Wennberg, California Institute of Technology, Pasadena, CA USA Steven Wofsy, Harvard University, Cambridge, MA, USA Debra Wunch, California Institute of Technology, Pasadena, CA, USA Yuk Yung, California Institute of Technology, Pasadena, CA, USA ii Contents OCO Science Team ......................................................................................................................... ii Contents ......................................................................................................................................... iii Executive Summary ....................................................................................................................... iv 1. OCO’s Contributions to Earth Science .................................................................... 1 1.1. Carbon Source/Sink Uncertainties ................................................................ 1 1.2. Advances in Carbon Cycle Science since the Selection of OCO ................. 3 1.2.1. Oceans ........................................................................................................... 5 1.2.2. Land .............................................................................................................. 7 1.2.3. Atmosphere ................................................................................................. 11 1.2.4. Source/Sink Modeling Tools ...................................................................... 13 1.2.5. Human Impacts ........................................................................................... 14 2. OCO Innovations ................................................................................................... 15 2.1. Instrument Payload ..................................................................................... 16 2.1.1. Spectral Ranges ........................................................................................... 16 2.1.2. Instrument Optical Design .......................................................................... 18 2.1.3. Spatial Sampling ......................................................................................... 19 2.2. Observing Modes ........................................................................................ 20 2.3. Advanced Retrieval Algorithms ................................................................. 21 2.4. World-class Spectroscopy ........................................................................... 23 2.5. Validation Strategy ..................................................................................... 24 3. Existing Space-based CO2 Remote Sensing Assets ............................................... 26 3.1. AIRS, TES and IASI ................................................................................... 26 3.2. GOSAT ....................................................................................................... 28 3.3. SCIAMACHY............................................................................................. 32 3.4. CanX-2 ........................................................................................................ 34 4. OCO in the Context of the Earth Science Decadal Survey .................................... 35 4.1. Explicit References to OCO in the NRC Earth Science Decadal Survey ... 35 4.2. OCO as Part of the Decadal Survey Vision and Priorities .......................... 35 4.3. OCO as a Necessary Precursor to ASCENDS ............................................ 36 5. OCO Delivers Critical Information for Policy Makers .......................................... 37 6. Conclusions ............................................................................................................ 38 Acknowledgements ....................................................................................................................... 39 References ..................................................................................................................................... 39 Glossary of Terms ......................................................................................................................... 49 iii ATMOSPHERIC CARBON DIOXIDE MEASUREMENTS FROM SPACE June 25, 2009 Executive Summary "I think a strong case can be made that the [Orbiting Carbon Observatory] should be reproduced as soon as possible. Here we are, on the verge of new international agreements, without thinking about how to monitor them. We are neglecting climate as an element of national security. We're not getting the information we need. Where are [climate] changes happening, and where are they going to happen?" -Ralph Cicerone, President of the National Academy of Sciences Speaking to Congress, 4 March 2009 Human activities now emit more than 32 billion tons of carbon dioxide (CO2) into the atmosphere each year, and the annual emissions rate has increased steadily since the dawn of the Industrial Age. Over half of this CO2 has been absorbed by natural sinks on land and in the ocean; the remainder stays in the atmosphere. Measurements made by the international carbon cycle science community have substantially improved our understanding of CO2 sources and sinks, and their relationship to climate change. Despite this progress, knowledge of the nature and location of CO2 sources and sinks, as well as the processes that will