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Chris Webster

Chris Webster's Photo

Address:

4800 Oak Grove Drive
M/S 183-401

Pasadena, CA 91109

Phone:

818.354.7478

Fax:

818.393.4485

Member of:

Science Division

JPL Fellow and Senior Research Scientist

Biography

Dr. Christopher R. Webster is a JPL Fellow and Senior Research Scientist who has formerly served as the Director of JPL's Microdevices Lab (MDL), and as the Program Manager of the Planetary Science Instruments Office (4X). From research at leading institutions in England (Bristol University), France (Paris Observatory), and the USA (Stanford University, JPL) he has pioneered the application of tunable laser spectroscopy to a wide variety of research in molecular structure, photochemistry, electrical discharge physics, and especially Earth atmospheric science emphasizing polar ozone, cloud physics and tropical transport. He is an expert in numerous laser techniques from UV to IR and has built several state-of-the-art instruments for gas and isotope ratio measurements on Earth aircraft (400 flights) and high-altitude balloons (22 flights). He has developed and built innovative miniature instruments for planetary missions to Mars, Venus, Ceres, Saturn and Titan, and is the Institutional PI on the Tunable Laser Spectrometer (TLS) instrument in the SAM analytical suite on the Curiosity Rover now in operation on the Martian surface, measuring atmospheric methane and H, C and O isotope ratios in the atmosphere and evolved from pyrolyzed rocks.

Education

  • B.Sc. (Hons) Chemical Physics, University of Reading (UK)
  • Ph.D. Molecular Spectroscopy, University of Bristol (UK) (1977)

Professional Experience

  • Jet Propulsion Laboratory (1981 - present)
    • Fellow, AGU (2018)
    • JPL Fellow (2017-present)
    • Senior Research Scientist (1990-present)
    • Director, Microdevices Lab (MDL) (2012-2016)
    • Program Manager, Planetary Science Instruments Office (2006-2014)
    • Institutional PI, TLS on SAM on Mars Science Lab (MSL) (2005-present)
    • Principal Investigator, numerous Earth and Planetary Science research grants
    • Element Leader for Atmospheric Chemistry (2000-2002)
    • Group Supervisor, Atmospheric Laser Spectroscopy Group (1985-present)
    • Section Manager for Earth and Oceanographic Science (1988-90)
    • Senior Scientist (1981-86)
  • Caltech Visiting - Full Professor, Geological and Planetary Sciences (1992-1994)
  • Stanford University - Postdoctoral Research Associate with Dick Zare (1979-81)
  • Observatoire de Paris, Meudon - Postdoctoral Researcher with Francois Rostas (1977-79)
  • Bristol University, England - Graduate student with Prof. Richard Dixon (1974-77)

Research Interests

  • Mars chemistry and habitability, isotope ratio biomarkers
  • Earth atmospheric chemistry and transport studied through in situ aircraft and balloon measurements usingstate-of-the-art laser spectroscopic instruments
  • Earth's hydrological cycle, cloud origin and water transport studied using water isotope ratios

Selected Awards

  • NASA Exceptional Scientific Achievement Medal (2016)
  • Ed Stone Award for Outstanding Research Paper (2016)
  • NASA Exceptional Technology Achievement Medal (2013)
  • NASA Exceptional Scientific Achievement Medal (2004)
  • Ed Stone Award for Outstanding Research Paper (2003)
  • NASA Exceptional Scientific Achievement Medal (1992)
  • NASA Group Achievement Awards (13 from 1992-present: team lead on 8)
  • NASA Certificates of Recognition for New Technology (12 from 1983)
  • Royal Society of London Student Fellowship (1977)

Selected Publications

Dr. Webster has published over 170 papers in refereed scientific journals.

  1. C.R. Webster et al., "Background levels of Mars' methane show strong seasonal variations", Science 360, 1093-1096 (2018).
  2. P.R. Mahaffy, C.R. Webster, et al., "The Imprint of Atmospheric Evolution in the D/H of Hesperian Clay Minerals on Mars", Science, 347, 412 (2015).
  3. C. R. Webster et al., "Mars Methane Detection and Variability at Gale Crater", Science, 347, 415-417 (2015).
  4. C.R. Webster et al., "Isotope Ratios of H, C, and O in CO2 and H2O of the Martian Atmosphere", Science, 341, 260-263 (2013).
  5. C.R. Webster et al., "Low Upper Limit to Methane Abundance on Mars", accepted: Science (2013).
  6. L.E. Christensen, B.Brunner, K. Truong, R.E. Mielke, C.R. Webster, and M. Coleman, "Measurement of Sulfur Isotope Compositions by Tunable Laser Spectroscopy of SO2", Analytical Chemistry, 10.1021/ac071040p (2007).
  7. C.R. Webster, "Measuring Methane and Its Isotopes 12CH4, 13CH4, CH3D on the Surface of Mars using in situ Laser Spectroscopy", Applied Optics, 44, 1226-1235, (2004).
  8. C.R. Webster et al., "Mars Laser Hygrometer", Applied Optics, 43, 4436-4445, (2004).
  9. C.R. Webster and A.J. Heymsfield, "Water Isotope Ratios D/H, 18O/16O and 17O/16O In and Out of Clouds Map Dehydration Pathways", Science, 302, 1742-1745, (2003).
  10. C.R. Webster et al., "Quantum cascade laser measurements of stratospheric methane (CH4) and nitrous oxide (N2O)", Applied Optics, 40, 321-326, (2001).
  11. C.R. Webster et al., "The response of lower stratospheric HCl/Cly to volcanic aerosol: Observations from aircraft, balloon, space shuttle, and satellite instruments", J. Geophys. Res., 105, 11,711-11,719, (2000).
  12. C.R. Webster, R.D. May, M. Allen, L. Jaeglé, "Balloon Profiles of Stratospheric NO2 and HNO3 for Testing the Heterogeneous Hydrolysis of N2O5 on Sulfate Aerosols", Geophys. Res. Letters 21, 53-56, (1994).
  13. C.R. Webster, R.D. May, C.A. Trimble, R.G. Chave and J. Kendall, "Aircraft (ER-2) Laser Infrared Absorption Spectrometer (ALIAS) for In-situ Stratospheric Measurements of HCl, N2O, CH4, NO2, and HNO", Applied Optics, 33, 454-472, (1994).
  14. C.R. Webster, R.D. May, D.W. Toohey, L.M. Avallone, J.G. Anderson and S. Solomon, "In-situ Measurements of the ClO/HCl Ratio: Heterogeneous Processing on Sulfate Aerosols and Polar Stratospheric Clouds", Geophys. Res. Letters 20, 2523-2526 (1993).
  15. C.R. Webster, R.D. May, D.W. Toohey, L.M. Avallone, J.G. Anderson, P. Newman, L. Lait, M.R. Schoeberl, J.W. Elkins and K.R. Chan, "Chlorine Chemistry on Polar Stratospheric Cloud Particles in the Arctic Winter", Science 261, 1130-1134 (1993).
  16. C. R. Webster, R. D. May, R. Toumi, and J. Pyle, "Active Nitrogen Partitioning and the Nighttime Formation of N2O5 in the Stratosphere: Simultaneous In-situ Measurements of NO, NO2, HNO3, O3, N2O, and jNO2 Using the BLISS Laser Spectrometer", J. Geophys. Res. 95, 13,851-13,866, (1990).
  17. C.R. Webster, S.P. Sander, R. Beer, R.D. May, R.G. Knollenberg, D.M. Hunten, and J. Ballard, "Tunable Diode Laser Infrared Spectrometer for In-situ Measurements of the Gas Phase Composition and Particle Size Distribution of Titan's Atmosphere", Appl. Opt. 29, 907-917, (1990).
  18. C.R. Webster, R.T. Menzies, E.D. Hinkley, "Infrared Laser Absorption: Theory and Applications", Laser Remote Chemical Analysis, Ch. 3, Ed. R. M. Measures, (1988).
  19. C.R. Webster, I.S. McDermid and C.T. Rettner, "Laser Optogalvanic Photodetachment Spectroscopy: A New Technique for Studying Photodetachment Thresholds with Application to I-", J. Chem Phys. 78, 646-651 (1983).
  20. C.R. Webster, P.J. Brucat and R.N. Zare, "Determination of the Electric Dipole Moment of the HSO Radical in its X2A"(000) and A2A'(003) Electronic States," J. Mol. Spectros. 92, 184-202 (l982).
  21. C.R. Webster and R.N. Zare, "Photochemical Isotope Separation of Hg l96 by Reaction with Hydrogen Halides," J. Phys. Chem. 35, l302-1305 (l98l).
  22. C.R. Webster, L. Woste and R.N. Zare, "Narrow Band UV Radiation (250 260 nm) by Intracavity Doubling a Single Mode Ring Dye Laser," Opt. Comm. 35, 435-440 (1980).
  23. R.N. Dixon and C.R. Webster, "The Determination of the Electric Dipole Moment of H2CS in its A,1A2 Excited State Using Dye Laser Electric Field Spectroscopy," J. Mol. Spectros. 70, 3l4-322 (l978).
  24. C.R. Webster, "Lasers for Listening to Molecules," New Scientist, 73, 383-385 (l977).

Projects

MSL - Mars Science Laboratory