Heather Graven

Research Interests:
Interactions of biogeochemistry and climate
Sources and sinks of anthropogenic CO₂
Radiocarbon in the global carbon cycle
Testing of atmospheric and oceanic transport models with chemical tracers
Observational method development

Education:
B.S. California Institute of Technology, 2001
M.S. Scripps Institution of Oceanography, 2003
Ph.D. Scripps Institution of Oceanography, 2008
Dissertation: “Advancing the use of radiocarbon in studies of global and regional carbon cycling with high precision measurements of ¹⁴C in CO₂ from the Scripps CO₂ Program”
Committee: Ralph Keeling, Thomas Guilderson, Devendra Lal, Jeff Severinghaus, Mark Thiemens, Ray Weiss

Publications:
Graven, H.D., and Gruber, N. Continental-scale enrichment of ¹⁴CO₂ from the nuclear power industry and resulting biases in observation-based estimates of fossil fuel-derived CO₂. In review, Geophysical Research Letters

Graven, H.D., Guilderson, T.P., and Keeling, R.F. Observations of radiocarbon in CO2 at La Jolla, California, 1992-2007. In review, Journal of Geophysical Research

Graven, H.D., Guilderson, T.P., and Keeling, R.F. Observations of radiocarbon in CO2 at seven global sampling sites in the Scripps flask network. In review, Journal of Geophysical Research

Graven, H.D., Stephens, B.B., Guilderson, T.P., Campos, T.L., Schimel, D.S., Campbell, J.E. and Keeling, R.F., 2009. Vertical profiles of biospheric and fossil fuel-derived CO₂ and fossil fuel CO₂:CO ratios from airborne measurements of Δ¹⁴C and CO₂ above Colorado, USA, Tellus B, 61 (3), 536-546.

Graven, H.D., Guilderson, T.P., and Keeling, R.F. 2007. Methods for high-precision ¹⁴C AMS measurement of atmospheric CO₂ at LLNL, Radiocarbon, 49 (2), 349-356.

Conference Presentations:
Graven H.D., and N. Gruber. Evolution of air-sea ¹⁴C fluxes in recent decades and implications for Δ¹⁴C gradients in atmospheric CO₂. Ocean Sciences Meeting, Portland, 2010.

Graven H.D., and N. Gruber. What caused the shifting meridional gradient of Δ¹⁴C in CO₂ from 1985 to 2006? 8th International Carbon Dioxide Conference, Jena, Germany, 2009.

Graven H.D., T.P. Guilderson, and R.F. Keeling. Trends and gradients in Δ¹⁴C of atmospheric CO₂ observed by the Scripps global flask network. 8th International Carbon Dioxide Conference, Jena, Germany, 2009.

Graven, H.D., T.P. Guilderson and R.F. Keeling. New Observations of Regional Variability in Delta-¹⁴C of Background CO₂ from the Scripps CO₂ Program. American Geophysical Union, Fall Meeting 2007.

Graven, H.D., T.P. Guilderson and R.F. Keeling. Delta-¹⁴CO₂ from the Scripps CO2 Program. WMO/IAEA Meeting of Experts on Carbon Dioxide, Other Greenhouse Gases, and Related Tracer Measurement Techniques, Helsinki, Finland, September 2007.

Graven, H.D., T.P. Guilderson and R.F. Keeling. Developing high-precision measurements of ¹⁴CO₂ for carbon cycle studies. North American Carbon Program Investigators Meeting, January 2007.

Graven, H.D., B.B. Stephens, R.F. Keeling, T.P. Guilderson, T.L. Campos and D.S. Schimel. Identifying CO2 sources with vertical profiles of Delta-¹⁴CO₂ above Colorado. American Geophysical Union, Fall Meeting 2006.

Graven, H.D., T.P. Guilderson and R.F. Keeling. High-precision AMS ¹⁴C measurements on atmospheric CO₂ samples at CAMS. 19th International Radiocarbon Conference, Oxford UK, April 2006.

Guilderson, T.P., H.D. Graven, K. Caldeira, R.F. Keeling and C.D. Keeling. ¹⁴CO₂ Measurements on the Scripps Flask Archive - A Unique Tool to Study the Carbon Cycle. 17th Annual Frontiers of Science Symposium of the National Academy of Sciences, Irvine CA, October 2005.

Graven, H.D., T.P. Guilderson, R.F. Keeling and C.D. Keeling. Developing precise measurements of background ¹⁴CO₂. 7th International Carbon Dioxide Conference, September 2005.

Graven, H.D., B.B. Stephens, J.B. Miller, R.F. Keeling, C. Gerbig, J. Lin and S.C. Wofsy. Airborne flask measurements of O₂/N₂, Ar/N₂, CO₂, and other species during COBRA-NA 2003. American Geophysical Union, Fall Meeting 2003.

Other Presentations:
ETH Zurich Ion Beam Physics Department, "Recent observations of Δ¹⁴C in atmospheric CO₂ from the Scripps CO₂ Program," 2009.

Zurich International School, "Where does the CO₂ go?", 2009

Lawrence Livermore National Laboratory, Center for Accelerator Mass Spectrometry, "High precision measurements of ¹⁴C in CO₂ from the Scripps CO₂ Program," 2008.

San Diego State University Ecology and Evolutionary Biology Seminar. "Radiocarbon in CO₂: a tool for identifying sources of CO₂." October 2007.

Public Forum on Understanding Climate Change, presented by the Mission Valley Rotary Club, San Diego. "Budgeting the fate of carbon emissions using ¹⁴CO₂." November 2004.

Newspaper article in the Boulder Daily Camera. "Flybys to gauge carbon dioxide levels near forests." April 30, 2004.

Newspaper article in the Boulder Daily Camera. "Flight to explore climate change." May 28, 2003.

Teaching Experience:
Co-advisor, Masters Thesis Project, 2010
Mentor, "Term Paper Writing for Environmental Sciences Graduate Students," 2008 & 2009
Teaching Assistant and Guest Lecturer, “The Atmosphere,” 2005 & 2006
Teaching Assistant, “Marine Chemistry,” 2006

Activities and Awards:
Reviewer for Geophysical Research Letters, Tellus, Radiocarbon and Naturwissenschaften, 2006-10
Reviewer for NOAA’s Global Carbon Cycle Program, 2009
NASA Earth System Science Graduate Research Fellowship, 2005-08
Associate Editor for the Journal of Environment and Development at UCSD, 2003-07
Steering Committee of SIO student group for Environmental Science and Policy, 2003-07
Tinker Field Research Grant, 2002
Dean’s Cup, awarded for outstanding undergraduate leadership, Caltech, 2001

Collaborative Field Campaigns:
Airborne Carbon in the Mountains Experiment (ACME), 2004
CO2 Budget and Regional Airborne Study (COBRA) – North America, 2003