Project Scientist

Research Interests:

  • AGAGE (Advanced Global Atmospheric Gases Experiment) http://agage.eas.gatech.edu/
  • Greenhouse gases
  • Halogenated trace gases
  • Ozone depleting compounds
  • Trace gas measurements (especially GC-FID/ECD/MSD)
  • Global warming
  • Top-down (measurement based) verification of bottom-up emission estimates
  • Atmospheric chemistry
  • Wildfire emissions
  • Long-range transport of pollutants

Degrees:

  • Diploma in Chemistry, University of Wuppertal
  • Doctor of Natural Sciences, Max Planck Institute for Chemistry, Mainz and Johannes Gutenberg University Mainz

Recent Publications

O'Doherty, S, Rigby M, Muhle J, Ivy DJ, Miller BR, Young D, Simmonds PG, Reimann S, Vollmer MK, Krummel PB, Fraser PJ, Steele LP, Dunse B, Salameh PK, Harth CM, Arnold T, Weiss RF, Kim J, Park S, Li S, Lunder C, Hermansen O, Schmidbauer N, Zhou LX, Yao B, Wang RHJ, Manning AJ, Prinn RG.  2014.  Global emissions of HFC-143a (CH3CF3) and HFC-32 (CH2F2) from in situ and air archive atmospheric observations. Atmospheric Chemistry and Physics. 14:9249-9258. AbstractWebsite

High-frequency, in situ observations from the Advanced Global Atmospheric Gases Experiment (AGAGE), for the period 2003 to 2012, combined with archive flask measurements dating back to 1977, have been used to capture the rapid growth of HFC-143a (CH3CF3) and HFC-32 (CH2F2) mole fractions and emissions into the atmosphere. Here we report the first in situ global measurements of these two gases. HFC-143a and HFC-32 are the third and sixth most abundant hydrofluorocarbons (HFCs) respectively and they currently make an appreciable contribution to the HFCs in terms of atmospheric radiative forcing (1.7 +/- 0.04 and 0.7 +/- 0.02 mW m(-2) in 2012 respectively). In 2012 the global average mole fraction of HFC-143a was 13.4 +/- 0.3 ppt (1 sigma) in the lower troposphere and its growth rate was 1.4 +/- 0.04 ppt yr(-1); HFC-32 had a global mean mole fraction of 6.2 +/- 0.2 ppt and a growth rate of 1.1 +/- 0.04 ppt yr(-1) in 2012. The extensive observations presented in this work have been combined with an atmospheric transport model to simulate global atmospheric abundances and derive global emission estimates. It is estimated that 23 +/- 3 Gg yr(-1) of HFC-143a and 21 +/- 11 Gg yr(-1) of HFC-32 were emitted globally in 2012, and the emission rates are estimated to be increasing by 7 +/- 5% yr(-1) for HFC-143a and 14 +/- 11% yr(-1) for HFC-32.

Li, S, Kim J, Park S, Kim S-K, Park M-K, Muhle J, Lee G, Lee M, Jo CO, Kim K-R.  2014.  Source Identification and Apportionment of Halogenated Compounds Observed at a Remote Site in East Asia. Environmental Science & Technology. 48:491-498.: American Chemical Society Abstract

The sources of halogenated compds. in East Asia assocd. with stratospheric ozone depletion and climate change are relatively poorly understood. High-precision in situ measurements of 18 halogenated compds. and carbonyl sulfide (COS) made at Gosan, Jeju Island, Korea, from Nov. 2007 to Dec. 2011 were analyzed by a pos. matrix factorization (PMF). Seven major industrial sources were identified from the enhanced concns. of halogenated compds. obsd. at Gosan and corresponding concn.-based source contributions were also suggested: primary aluminum prodn. explaining 37% of total concn. enhancements, solvent usage of which source apportionment is 25%, fugitive emissions from HCFC/HFC prodn. with 11%, refrigerant replacements (9%), semiconductor/electronics industry (9%), foam blowing agents (6%), and fumigation (3%). Statistical trajectory anal. was applied to specify the potential emission regions for seven sources using back trajectories. Primary aluminum prodn., solvent usage and fugitive emission sources were mainly contributed by China. Semiconductor/electronics sources were dominantly located in Korea. Refrigerant replacement, fumigation and foam blowing agent sources were spread throughout East Asian countries. The specified potential source regions are consistent with country-based consumptions and emission patterns, verifying the PMF anal. results. The industry-based emission sources of halogenated compds. identified in this study help improve our understanding of the East Asian countries' industrial contributions to halogenated compd. emissions. [on SciFinder(R)]

Mahieu, E, Zander R, Toon GC, Vollmer MK, Reimann S, Mühle J, Bader W, Bovy B, Lejeune B, Servais C, Demoulin P, Roland G, Bernath PF, Boone CD, Walker KA, Duchatelet P.  2014.  Spectrometric monitoring of atmospheric carbon tetrafluoride (CF4) above the Jungfraujoch station since 1989: evidence of continued increase but at a slowing rate. Atmos. Meas. Tech.. 7:333-344.: Copernicus Publications AbstractWebsite
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Hall, BD, Engel A, Mühle J, Elkins JW, Artuso F, Atlas E, Aydin M, Blake D, Brunke EG, Chiavarini S, Fraser PJ, Happell J, Krummel PB, Levin I, Loewenstein M, Maione M, Montzka SA, O'Doherty S, Reimann S, Rhoderick G, Saltzman ES, Scheel HE, Steele LP, Vollmer MK, Weiss RF, Worthy D, Yokouchi Y.  2014.  Results from the International Halocarbons in Air Comparison Experiment (IHALACE). Atmos. Meas. Tech.. 7:469-490.: Copernicus Publications AbstractWebsite
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Arnold, T, Ivy DJ, Harth CM, Vollmer MK, Mühle J, Salameh PK, Steele PL, Krummel PB, Wang RHJ, Young D, Lunder CR, Hermansen O, Rhee TS, Kim J, Reimann S, O'Doherty S, Fraser PJ, Simmonds PG, Prinn RG, Weiss RF.  2014.  HFC-43-10mee atmospheric abundances and global emission estimates. Geophysical Research Letters. :2013GL059143. AbstractWebsite

We report in situ atmospheric measurements of HFC-43-10mee (C5H2F10, 1,1,1,2,2,3,4,5,5,5-decafluoropentane) from seven observatories at various latitudes, together with measurements of archived air samples and recent Antarctic flask air samples. The global mean tropospheric abundance was 0.21 ± 0.05 ppt (parts-per-trillion, dry air mole fraction) in 2012, rising from 0.04 ± 0.03 ppt in 2000. We combine the measurements with a model and inverse method to estimate rising global emissions –– from 0.43 ± 0.34 Gg yr-1 in 2000 to 1.13 ± 0.31 Gg yr-1 in 2012 (~1.9 Tg CO2-eq yr-1 based on a 100-yr global warming potential of 1,660). HFC-43-10mee –– a cleaning solvent used in the electronics industry –– is currently a minor contributor to global radiative forcing relative to total HFCs; however, our calculated emissions highlight a significant difference from the available reported figures and projected estimates.

Fraser, PJ, Dunse BL, Manning AJ, Walsh S, Wang RHJ, Krummel PB, Steele LP, Porter LW, Allison C, O'Doherty S, Simmonds PG, Mühle J, Weiss RF, Prinn RG.  2014.  Australian carbon tetrachloride emissions in a global context. Environmental Chemistry. 11:77-88. AbstractWebsite

Global (1978-2012) and Australian (1996-2011) carbon tetrachloride emissions are estimated from atmospheric observations of CCl4 using data from the Advanced Global Atmospheric Gases Experiment (AGAGE) global network, in particular from Cape Grim, Tasmania. Global and Australian emissions are in decline in response to Montreal Protocol restrictions on CCl4 production and consumption for dispersive uses in the developed and developing world. However, atmospheric data-derived emissions are significantly larger than 'bottom-up' estimates from direct and indirect CCl4 production, CCl4 transportation and use. Australian CCl4 emissions are not a result of these sources, and the identification of the origin of Australian emissions may provide a clue to the origin of some of these 'missing' global sources. Journal compilation © CSIRO 2014.