ESSL Lab Annual Report: 2007: Research Catalog: TIIMES: Britton Stephens

ESSL LAR

Research Catalog: TIIMES

Britton Stephens Scientist II TIIMES - EOL - RAF BEACHON & BGS Contact Information: PO Box 3000, Boulder, CO 80307-3000 Office: Jeffco-143 Telephone: 303-497-1018 Email: stephens@ucar.edu Home Page

Project Summary: Click on picture to view the entire figure Measurements show that about 40% of the carbon dioxide emitted through fossil fuels and deforestation remains in the atmosphere, while an estimated 30% is absorbed by trees and other plants and another 30% by the oceans (see inset). Computer models have indicated that forests in the mid and upper latitudes absorb a high amount of carbon dioxide, while tropical forests emit the gas because of deforestation. But a new study led by NCAR's Britton Stephens shows that the two regions are more balanced than previously thought, with intact tropical forests playing a major role in absorbing carbon dioxide. UCAR News Release (Illustration by Steve Deyo, ©UCAR. News media terms of use History: Britton Stephens’ TIIMES research is focused on advancing our understanding of global carbon cycling and supporting the biogeosciences research community. This work has included airborne and ground-based field observations targeting regional scale carbon fluxes, analyses of background observations to investigate global carbon cycling, and instrument development for tower and aircraft applications. Click on picture to view the entire figure Airborne Carbon in the Mountains Experiment (ACME-07), Flight 7June 2007. Figure produced by S. Aulenbach, A. Desai, and D. Moore FY07 Activities: Stephens completed an analysis of light-aircraft vertical CO2 profiles measured at 12 global sites by 7 international laboratories. The results, which were published in Science Magazine, suggest a significant revision to the consensus view of the global carbon cycle by revealing systematic biases in atmospheric models that previously predicted large northern terrestrial CO2 uptake and large tropical CO2 releases [see Figure to the right - video interview]. Stephens was also the lead-PI on the Airborne Carbon in the Mountains Experiment (ACME-07). This campaign was carried out on the University of Wyoming King Air between April and August and included 63 hours of flights investigating CO2 exchanges in the Colorado Rocky Mountains. The ACME-07 payload included the NCAR Community Airborne Oxygen Instrument (AO2) which was completed this year by Stephens and TIIMES and EOL colleagues. Click on picture to view the entire figure View out window of the Wyoming King Air during the ACME campaign, as it passes Storm Peak Laboratory which is one of the Rocky RACCOON sites (photo credit: Britt Stephens). Stephens continues to maintain the Regional Atmospheric Continuous CO2 Network in the Rocky Mountains (Rocky RACCOON), as a key contribution to the multi-agency North American Carbon Program (NACP). A fifth Autonomous Inexpensive Robust CO2 Analyzer (AIRCOA) site was added this year in collaboration with the University of Utah at the Entrada Field Station. Stephens and CU graduate student Sherri Heck are analyzing the RACCOON data and working to incorporate data into data assimilation and modeling tools. FY08 Plans: Stephens will deploy the Multiple Enclosure Device for Unfractionated Sampling of Air (MEDUSA) flask sampler as part of the Brazilian Amazon Regional Carbon Airborne study (BARCA) scheduled for September 2008 and both the MEDUSA sampler and the AO2 instrument on the NCAR GV as part of the START08/pre-HIPPO campaign in Spring of ’08. Stephens and colleagues will deploy a sixth AIRCOA unit as part of RACCOON at Roof Butte on the Navajo Reservation in Northeastern Arizona this fall and a seventh unit at Mt. Kenya in Africa this winter. Data analysis and paper writing will focus on the results from the ACME-07 and RACCOON projects as well as previous campaigns.

News Articles Relating to Research - Online : Aircraft measurements reveal missing carbon sink, electronic, USA, June 2007 As It Happens - Tree Planting Useless (audio), audio, CAN, June 2007 Canada's trees not a fix for its pollution, electronic, CAN, June 2007 Carbon Cycle, electronic, USA, June 2007 Geschrumpftes Potential, audio, DEU, June 2007 Jungles drink up greenhouse gases. They absorb 2.4 tons of human-produced carbon dioxide a year, a study by Colorado scientists shows., electronic, Denver USA, June 2007 Missing carbon mystery: Case solved?, electronic, USA, June 2007 Mysteries of carbon uptake unravel: Less northern forest absorption, more in tropics, electronic, Boulder, June 2007 Northern Forests Less Effective Than Tropical Forests in Reducing Global Warming, electronic, Arlington USA, June 2007 Scientists Close in on Missing Carbon Sink; Northern Forests Less Effective Than Expected in Reducing Global Warming, electronic, Boulder USA, June 2007 Scientists Hunting for Missing Carbon May Have Been Looking in the Wrong Place, electronic, USA, June 2007 Study: All forests not created equal, electronic, USA, June 2007 Where does all the carbon go?, electronic, GBR, June 2007

Presentations: Aircraft CO2 Observations and Global Carbon Budgeting, IMAGe/MSRI Summer Graduate Workshop on Data Assimilation for the Carbon Cycle, Boulder, CO, July, 2007 [PPT] Aircraft CO2 Observations and the Missing Carbon Sink, NCAR Directors’ Committee monthly meeting, Boulder, CO, June, 2007 [PPT] Light Aircraft CO2 Observations and the Global Carbon Cycle, NCAR TIIMES and EOL Seminar Series, Boulder, CO, April, 2007 [PPT] Regional Needs and Instrumentation for CO2 Observations, ASP Colloquium: Regional Biogeochemistry, Boulder, CO, June, 2007 [PPT] Regional to Global Carbon Cycling, lecture given to University of Nevada graduate field course in atmospheric sciences, Storm Peak Laboratory, CO, January, 2007 [PPT and embedded MPG, MPG] The Vertical Distribution of Atmospheric CO2 and the Latitudinal Partitioning of Global Carbon Fluxes, NCAR TIIMES Management and Science Advisory Committee meeting, Boulder, CO, December, 2006 [PPT] There's a Rectifier in my Closet: Vertical CO2 Transport and Latitudinal Flux Partitioning, TransCom Meeting, Purdue, IN, April, 2007 [PPT]

TIIMES External Collaborators: Dave Bowling, University of Utah Sherri Heck, University of Colorado & NCAR Ralph Keeling, Scripps Institution of Oceanography Andrew Manning, University of East Anglia John Miller, National Oceanic & Atmospheric Administration (NOAA) - GMD Russ Monson, University of Colorado Steve Wofsy, Harvard University

Publications:
Sun, J., S. P. Burns, A. C. Delaney, S. P. Oncley, A. A. Turnipseed, B. B. Stephens, D. H. Lenschow, M. A. LeMone, R. K. Monson, D. E. Anderson, 2007: CO2 Transport over Complex Terrain. Agric. For. Meteorol., 145, 1-21, doi: 10.1016/j.agrformet.2007.02.007. Stephens, B. B., K. R. Gurney, P. P. Tans, C. Sweeney, W. Peters, L. Bruhwiler, P. Ciais, M. Ramonet, P. Bousquet, T. Nakazawa, S. Aoki, T. Machida, G. Inoue, N. Vinnichenko, J. Lloyd, A. Jordan, M. Heimann, O. Shibistova, R. L. Langenfelds, L. P. Steele, R. J. Francey, A. S. Denning, 2007: Weak northern and strong tropical land carbon uptake from vertical profiles of atmospheric CO2. Science, 316, 1732-1735, doi: 10.1126/science.1137004. Stephens, B. B., P. S. Bakwin, P. P. Tans, R. M. Teclaw, D. D. Baumann, 2007: Application of a differential fuel-cell analyzer for measuring atmospheric oxygen variations. J. Atmos. Ocean. Technol., 24, 82-94, doi: 10.1175/JTECH1959.1. Stephens, B. B., A. Watt, G. Maclean, 2006: An autonomous inexpensive robust CO2 anyalyer (AIRCOA). 13th WMO/IAEA Carbon Dioxide Concentration and Related Tracers Measurement Techniques, TD1359, 95-99,

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