School of GeoSciences

School of GeoSciences


Tim Arnold

Lecturer in the Global Change Research Institute
Senior Research Scientist at the National Physical Laboratory (London)

Open positions

We have a PhD studentship to start in October 2017 looking at how new types of measurements can be used to understand greenhouse gas sources and sinks. Please get in touch for information how how to apply.


My research helps improve our understanding of the sources of greenhouse gases. I am especially interested in the development and use of high-precision ground-based measurements that are sensitive to emissions on local to regional to global scales. Emissions can be quantified from these measurements using atmospheric transport models within a mathematical inversion framework. Developing novel measurement methods and improving the quality of information within this framework holds promise to reduce emissions estimate uncertainties and help focus climate change mitigation efforts.

I have a joint position between the National Physical Laboratory in London and the University of Edinburgh. The National Physical Laboratory is the UK's National Measurement Institute, which is responsible for traceability, accuracy and consistency of measurement from fundamental science through to delivery of services. At NPL I work in the Emissions and Atmospheric Metrology group - a team of 20+ scientists helping a range of organisations and companies quantify gaseous and particulate emissions important to climate and air quality.

Tim's Biography

Before joining the National Physical Laboratory and the University of Edinburgh in 2016 I was at the Met Office Hadley Centre (2014-2016). Prior to this, I spent more than five years in the USA at the University of California, San Diego at the Scripps Institution of Oceanography as a postdoc studying atmospheric composition change (2009-2014). My undergraduate studies were in Natural Sciences at the University of Cambridge (2001-2005) and I followed this with a PhD in isotope geochemistry in the Earth Science and Engineering Department at Imperial College London (2005-2009).


Bergamaschi, P., Karstens, U., Manning, A. J., Saunois, M., Tsuruta, A., Berchet, A., Vermeulen, A. T., Arnold, T., Janssens-Maenhout, G., Hammer, S., Levin, I., Schmidt , M., Ramonet, M., Lopez, M., Lavric, J., Aalto, T., Chen, H., Feist, D. G., Gerbig, C., Haszpra, L., Hermansen, O., Manca, G., Moncrieff, J., Meinhardt, F., Necki, J., Galkowski, M., O'Doherty, S., Paramonova, N., Scheeren, H. A., Steinbacher, M., and Dlugokencky, E.: Inverse modelling of European CH4 emissions during 2006–2012 using different inverse models and reassessed atmospheric observations, Atmos. Chem. Phys. Discuss. 2017, doi:10.5194/acp-2017-273, in review.

Brunner, D., Arnold, T., Manning, A., Thompson, R.L., Maione, M., O'Doherty, S., Reimann, S., Comparison of four inverse modelling systems applied to the estimation of HFC-125, HFC-134a and SF6 emissions over Europe, Atmos. Chem. Phys. Discuss. 2017, doi:10.5194/acp-2017-19, in review.

Simmonds, P.G., M. Rigby, A. Manning, M. Lunt, S. O'Doherty, D. Young, A. McCulloch, P. Fraser, S. Henne, M. Vollmer, S. Reimann, A. Wenger, J. Mulhe, C. Harth, P. Salameh, T. Arnold, R. Weiss, P. Krummel, P. Steele, B. Dunse, B. Miller, C. Lunder, O. Hermansen, N. Schmidbauer, T. Saito, Y. Yokouchi, S. Park, S. Li, B. Yao, L. Zhou, J. Arduini, M. Maione, R. Wang, and R. Prinn, Global and regional emissions estimates of 1,1-difluoroethane (HFC-152a, CH3CHF2) from in situ and air archive observations, Atmos. Chem. Phys. 2016, 16, 365–382.

Lunt, MF, Rigby, M, Ganesan, AL, Manning, AJ, Prinn, RG, O'Doherty, S, Mühle, J, Harth, CM, Salameh, PK, Arnold, T, Weiss, RF, Saito, T, Yokouchi, Y, Krummel, PB, Steele, LP, Fraser, PJ, Li, S, Park, S, Reimann, S, Vollmer, MK, Lunder, C, Hermansen, O, Schmidbauer, N, Maione, M, Arduini, J, Young, D, and Simmonds, PG, Reconciling reported and unreported HFC emissions with atmospheric observations. Proceedings of the National Academy of Sciences of the United States of America 2015, 112, 5927–5931.

Arnold, T., Markovic T, Kirk GJD, Schönbächler M, Rehkämper M, Zhao FJ, Weiss DJ, Weiss DJ, Iron and zinc isotope fractionation during uptake and translocation in rice (Oryza sativa) grown in oxic and anoxic soils, Comptes Rendus Geoscience. 2015, 347, 397–404.

Patra, P.K., Krol, M.C., Montzka, S.A., Arnold, T., Atlas, E. L., Lintner, B.R., Stephens, B. B., Xiang, B., Elkins, J.W., Fraser, P. B., Ghosh, A., Hintsa, E.J., Hurst, D.F., Ishijima, K., Krummel, P.B., Miller, B.R., Miyazaki, K., Moore, F.L., Mühle, J., O’Doherty, S., Prinn, R.G., Steele, L.P., Takigawa, M., Wang, H.J., Weiss, R.F., Wofsy, S.C., Young, D., Observational evidence for interhemispheric hydroxyl-radical parity, Nature 2014, 513, 219–223.

O'Doherty, S., Rigby, M., Mühle, J., Ivy, D.J., Miller, B.R., Young, D., Simmonds, P.G., Reimann, S., Vollmer, M., Krummel, P.B., Fraser, P.J., Steele, L.P., Dunse, B., Salameh, P.K., Harth, C.M., Arnold, T., Weiss, R.F., Kim, J., Park, S., Li, S., Lunder, C., Hermansen, O., Schmidbauer, N., Zhou, L.X., Yao, B., Wang, R.H.J., Manning, A., Prinn, R.G., Global emissions of HFC-143a (CH3CF3) and HFC-32 (CH2F2) from in situ and air archive atmospheric observations, Atmospheric Chemistry and Physics 2014, 14, 6471-6500.

Kim, J., Fraser, P.J., Li, S., Mühle, J., Ganesan, A.L., Krummel, P.B., Steele, L.P., Park, S., Kim, S.-K., Park, M.-K., Arnold, T., Harth, C.M., Salameh, P.K., Prinn, R.G., Weiss, R.F., Kim, K.-R., Quantifying aluminum and semiconductor industry perfluorocarbon emissions from atmospheric measurements, Geophysical Research Letters 2014, 41, 4787–4794.

Arnold, T., Ivy, D.J., Harth, C.M., Vollmer M.K., Mühle, J., Salameh, P.K., Steele, L.P., Krummel, P.B., Wang, R.H.J., Young, D, Lunder, C.R., Hermansen, O., Rhee, T.S., Kim, J., Reimann, S., O'Doherty, S., Fraser, P.J., Simmonds, P.G., Prinn, R.G., and Weiss, R.F., HFC‑43‑10mee atmospheric abundances and global emission estimates, Geophysical Research Letters 2014, 41(6), 2228-2235.

Rigby, M., Prinn, R.G., O’Doherty, S., McCulloch, A., Miller, B., Mühle, J., Harth, C., Salameh, P., Arnold, T., Weiss, R., Krummel, P., Steele, L.P., Fraser, P.J., Ivy, D., Young, D., Simmonds, P., Recent and future trends in synthetic greenhouse gas radiative forcing. Geophysical Research Letters 2014, 41(7), 2623-2630.

Arnold, T., Harth, C.M., Mühle, J., Salameh, P.K., Manning, A.J., Ivy, D.J., Steele, L.P., Kim, J., Petrenko, V.V., Severinghaus, J.P., Baggenstos, D. and Weiss, R.F., Nitrogen trifluoride global emissions estimated from updated atmospheric measurements, Proceedings of the National Academy of Sciences USA 2013, 110, 2029-2034.

Arnold, T., Mühle, J., Salameh, P.K., Harth, C.M., Ivy, D.J., Weiss, R.F., Automated measurement of nitrogen trifluoride in ambient air, Analytical Chemistry 2012, 84, 4798-4804.

Ivy, D.J., Arnold, T., Harth, C.M., Steele, L.P., Mühle, J., Rigby, M., Salameh, P.K., Leist, M., Krummel, P.B., Fraser, P.J., Weiss, R.F., Prinn, R.G., Atmospheric histories and growth trends of C4F10, C5F12, C6F14, C7F16 and C8F18, Atmospheric Chemistry and Physics 2012, 12, 4313-4325.

Li, S., Kim, J., Kim, K-R., Kim, S-K., Park, M-K., Mühle, J., Stohl, A., Kang, D-J., Arnold, T., Harth, C.M., Salameh, P.K., Weiss, R.F., Emissions of halogenated compounds in East Asia determined from measurements at Jeju Island, Korea, Environmental Science and Technology 2011, 45, 5668-5675.

Vollmer, M.K., Miller, B.R., Rigby, M., Reimann, S., Mühle, J., Krummel, P.B., O'Doherty, S., Kim, J., Rhee, T.S., Weiss, R.F., Fraser, P.J., Simmonds, P.G., Salameh, P.K., Harth, C.M., Wang, R.H.J., Steele, L.P., Young, D., Lunder, C.R., Hermansen, O., Ivy, D., Arnold, T., Schmidbauer, N., Kim, K.-R., Greally, B.R., Hill, M., Leist, M., Wenger, A., Prinn, R.G., Atmospheric histories and global emissions of the anthropogenic hydrofluorocarbons (HFCs) HFC-365mfc, HFC-245fa, HFC-227ea, and HFC-236fa, Journal of Geophysical Research 2011, 116, D08304.

Dekova, V.M., Cuadros, J., Kamenov, G.D., Weiss, D, Arnold, T., Basak, C., Rochette, P., Metalliferous sediments from the H.M.S. Challenger voyage (1872-1876), Geochimica Et Cosmochimica Acta 2010, 74, 5019-5038.

Arnold, T., Schonbachler, M., Rehkamper, M., Dong, S., Zhao, F.J., Kirk, G.J.D., Coles, B.J., Weiss, D.J., Measurement of zinc stable isotope ratios in biogeochemical matrices by double spike MC-ICPMS and determination of the isotope ratio pool available for plants from soil, Analytical and Bioanalytical Chemistry 2010, 398, 3115-3125.

Arnold, T., Kirk, G.J.D., Wissuwa, M., Frei, M., Zhao, F.J., Mason, F.D., Weiss, D.J., Evidence for the mechanisms of Zn uptake by rice using isotope fractionation, Plant, Cell & Environment 2010, 33, 370-381.

Arnold, T., Zinc and Iron isotopes at the plant-soil interface, PhD thesis – Imperial College London, 2009.

Gioia, S., Weiss, D., Coles, B., Arnold, T., Babinski, M., Accurate and precise zinc isotope ratio measurements in urban aerosols. Analytical Chemistry 2008, 80, 9776-9780.

Arnold, T., Harvey, J. N., Weiss, D. J., An experimental and theoretical investigation into the use of H2 for the simultaneous removal of ArO+ and ArOH+ isobaric interferences during Fe isotope ratio analysis with MC-ICP-MS. Spectrochimica Acta Part B: Atomic Spectroscopy 2008, 63, 666-672.

Weiss, D. J., Schoenberg, R., McLaughlin, M., Rehkamper, M., Campbell, P. G. C., Arnold, T., Chapman, J., Peel, K.; Gioia, S., Kirby, J., Application of non-traditional stable isotope systems to the study of sources and fate of metals in the environment. Environmental Science & Technology 2008, 42, 655-664.

Peel, K., Weiss, D., Chapman, J., Arnold, T., Coles, B., A simple combined sample-standard bracketing and inter-element correction procedure for accurate mass bias correction and precise Zn and Cu isotope ratio measurements. Journal of Analytical Atomic Spectrometry 2008, 23, 103-110.

Weiss, D. J., Rausch, N., Mason, T. F. D., Coles, B. J., Wilkinson, J. J., Ukonmaanaho, L., Arnold, T., Nieminen, T. M., Atmospheric deposition and isotope biogeochemistry of zinc in ombrotrophic peat. Geochimica Et Cosmochimica Acta 2007, 71, 3498-3517.

Watkins, R., Weiss, D., Dubbin, W., Peel, K., Coles, B., Arnold, T., Investigations into the kinetics and thermodynamics of Sb(III) adsorption on goethite (alpha-FeOOH). Journal of Colloid and Interface Science 2006, 303, 639-646.