Hannah Christensen

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Hannah Christensen

Associate Professor

Hannah M. Christensen

I hold an Associate Professorship in Physical Climate in conjunction with a Tutorial Fellow at Wadham College. I am also a Natural Environment Research Council Independent Research Fellow until December 2023.


N.B. Publishing under H. M. Arnold prior to May 2014, and under H. M. Christensen after May 2014.

For an up to date publications list, please visit my personal webpage.

Roberts, M. J., Vidale P. L., Senior, C., Hewitt, H. T., Chang, P., Christensen, H. M., Danilov, S., Demory, M.-E., Griffies, S. M., Haarsma, R., Jung, T., Martin, G. Minobe, S., Ringler, T., Satoh, M., Schiemann, R. Scoccimarro, E., Stephens, G., Wehner, M. F., The benefits of global high-resolution for climate simulation: process-understanding and the enabling of stakeholder decisions at the regional scale. Submitted to Bull. Amer. Met. Soc

Strømmen, K, Christensen, H. M., Berner, J. and Palmer, T. N., The impact of stochastic parametrisations on the representation of the Asian summer monsoon. In press, Climate Dynamics

Leutbecher, M., Lock, S.-J., Ollinaho, P., Lang, S., Balsamo, G., Bechtold, P., Bonavita, M., Christensen, H. M., Diamantakis, M., Dutra, E., English, S., Fisher, M., Forbes, R., Goddard, J., Haiden, T., Hogan, R., Juricke, S., Lawrence, H., MacLeod, D., Magnusson, L., Malardel, S., Massart, S., Sandu, I., Smolarkiewicz, P., Subramanian, A., Vitart, F., Wedi, N., Weisheimer, A., Stochastic representations of model uncertainties at ECMWF: State of the art and future vision. In press, Q. J. Roy Meteor Soc.

Christensen, H. M., Lock, S.-J., Moroz, I. M., and Palmer, T. N., 2017, Introducing Independent Patterns into the Stochastically Perturbed Parametrisation Tendencies (SPPT) scheme. Q. J. Roy Meteor Soc. 143 (706), 2168–2181

Davini, P., von Hardenberg, J., Corti, S., Christensen, H. M., Juricke, S., Subramanian, A., Watson, P. A. G., Weisheimer, A. and Palmer, T., 2017, Climate SPHINX: evaluating the impact of resolution and stochastic physics parameterisations in the EC-Earth global climate model. Geosci. Model Dev., 10 1383–1402.

Berner, J., Achatz, A., Batte, L., de la Camara, A., Christensen, H. M., Colangeli, M., Coleman, D., Crommelin, D., Dolaptchiev, S. I., Franzke, C. L. E., Friederichs, P., Imkeller, P., Jarvinen, H., Juricke, S., Kitsios, V., Lott, F., Lucarini, V., Mahajan, S., Palmer, T. N., Penland, C., Sakradzija, M., von Storch, J.-S., Weisheimer, A., Weniger, M., Williams, P. D., and Yano, J.-I., 2017, Stochastic Parameterization: Towards a new view of Weather and Climate Models. Bull. Amer. Met. Soc. 98(3), 565–588.

Christensen, H. M., Berner, J., Coleman, D., and Palmer, T. N., 2017, Stochastic Parametrisation and the El Nin ̃o-Southern Oscillation. J. Climate. 30(1), 17-38.

Christensen, H. M., 2016, Contribution to the discussion on ‘Of quantiles and expectiles: consistent scoring functions, Choquet representations and forecast rankings’ by W Ehm et al. Journal of the Royal Statistical Society B. 78 (3), 505–562.

Christensen, H. M., 2016, Can randomness reduce uncertainty? The use of stochastic physics in weather and climate prediction, presented at the Royal Astronomical Society Astronomy and Geophysics Meeting, November 2015. The Observatory (April 2016)

Christensen, H. M., Moroz, I. M. and Palmer, T. N., 2015, Stochastic and perturbed parameter representations of model uncertainty in convection parametrization. J. Atmos. Sci., 72, 2525–2544.

Christensen, H. M., 2015, Decomposition of a New Proper Score for Verification of Ensemble Forecasts. Mo. Weath. Review, 143, 1517–1532.

Christensen, H. M., Moroz, I. M. and Palmer, T. N., 2015, Simulating Weather Regimes: impact of stochastic and perturbed parameter schemes in a simple atmospheric model. Climate Dynamics. 44(7), 2195-2214

Christensen, H. M., Moroz, I. M. and Palmer, T. N., 2015, Evaluation of ensemble forecast uncertainty using a new proper score: application to medium-range and seasonal forecasts.. Q. J. Roy. Meteor. Soc. 141(687), 538-549.

Watson, P. A. G., Christensen, H. M., and Palmer, T. N., 2015, Does the ECMWF IFS convection parameterisation with stochastic physics correctly reproduce relationships between convection and the large-scale state? J. Atmos. Sci., 72, 236-242.

Arnold, H. M., 2013, "Stochastic Parametrisation and Model Uncertainty", Doctoral Thesis, University of Oxford.

Arnold, H. M., 2013, Should weather and climate prediction models be deterministic or stochastic? Weather, 68(10), p264.

Arnold, H. M., Moroz, I. M. and Palmer, T. N., 2013, Stochastic Parametrizations and Model Uncertainty in the Lorenz '96 System,Phil Trans R Soc A, 371: 20110479

Invited Conference Talks and Seminars

NCAS-Climate Seminar, University of Reading UK (date tbc)
Applied Math Seminar, University of California, Berkeley, USA. (date tbc)
Clouds and Boundary Layer Processes Workshop, ETH Zürich, Switzerland. 13-15 Jun 2016
Computational Statistics Seminar, Heidelberg Institute for Theoretical Studies, Germany, Mar 2016
American Geophysical Union Fall Meeting, San Francisco, CA, USA Dec 2015
Royal Astronomical Society Ordinary Meeting (Keith Runcorn Prize Lecture), London, UK Nov 2015
Conference on Meteorology And Climate - Modeling for Air Quality (unable to accept invitation), Sacramento, CA, USA. Sep 2015
OpenIFS user meeting, ECMWF, Reading, UK. Jun 2015
Stochastic Parametrisation Workshop, ECMWF, Reading, UK. Mar 2015
Dynamical Systems Seminar Series, University of Colorado Boulder, CO, USA. Sep 2014
Workshop on Representing Uncertainty Across Timescales, Met Office, Exeter. Mar 2014
Atmospheric, Oceanic and Planetary Physics Seminar Series, University of Oxford. Mar 2014
CWC/SRM Meeting on Global Climate Modelling, Institute of Physics, London. Feb 2014
Centre for Atmospheric Science Seminar Series, University of Cambridge. Feb 2014
Internal Seminar Series, European Centre for Medium Range Weather Forecasts, Reading. Jan 2014


Lloyds Science of Risk Peter Taylor Prize, runner up, for outstanding contribution of insurance understanding of natural hazards

This prize was awarded at the Lloyds Science of Risk conference 2016 for our paper Stochastic Parametrisation and the El Nin ̃o-Southern Oscillation, J. Climate (in press).

RAS Keith Runcorn Prize 2014: best doctoral thesis in Geophysics

I was invited to give the Keith Runcorn Prize lecture at the RAS Ordinary Meeting in November 2015.

Corpus Christi Junior Research Fellowship

From October 2013 to September 2016, I was a Junior Research Fellow at Corpus Christi College, Oxford.

Jesus College Graduate Scholarship

From September 2012, I have been awarded a Graduate Scholarship by Jesus College.

SET for Britain

I recently won the Silver Award in the SET for Britain 2012 Competition held in the House of Commons on Monday 12th March.

I discussed my poster, "Reliably Predicting Uncertainty in Weather and Climate Forecasts", with my local MPs, Gareth Thomas (Harrow West) and Andrew Smith (Oxford East), as well as with my fellow participants.

Thanks to the Society of Biology for the photos.

AOPP Johnson Prize

I was awarded the Atmospheric, Oceanic and Planetary Physics Johnson Prize for my Transfer of Status report. (October 2011)

DPhil (=PhD) Applicants

I am glad to be accepting applications for PhD students to join my group.

UK applicants should apply through the NERC-Oxford Doctoral Training Partnership in Environmental Research (Physical Climate stream), which provides fully funded studentships.

Overseas applicants should apply directly to the subdepartment. Scholarships are available through the centralised DPhil funding database.

Potential projects are listed through the DTP and AOPP project pages. These are illustrative of potential areas of research in our group. It is expected that projects would evolve to suit the interests and expertise of the student.


I am a Tutorial Fellow at Wadham College, with responsibility for teaching the first year maths-for-physicists courses, CP3 and CP4.

Past teaching:

  • Lectureship in Physics, Corpus Christi College, Oxford (2018-20).
  • NERC Doctoral Training Programme, Advanced Training Workshop on Chaos and Uncertainty in Weather Forecasts, 2016
  • Classical Mechanics tutorials for Part A (second year) Mathematicians, 2011, 2013
  • Flows, Fluctuations and Complexity tutorials for Part B (third year) physicists, 2012-2019.
  • Atmospheric, Oceanic and Planetary Physics classes for Part C (fourth year) physicists in 2016-17.

I have supervised several summer undergraduate student projects:
2016: Ben Macrae. "Extreme weather and circulation regimes in the Weather@Home ensemble", with Peter Watson
2015: Michael Varley. "Improving Probabilistic Weather and Climate Predictions", with Peter Watson
2013: Tom Bolton. "Stochastic processors and inexact computing for weather and climate prediction" with Peter Dueben

Media: Podcasts

Oxford Sparks podcast, published online 4th Nov 2016

“In Press” UK science podcast and accompanying blog, published online, 15th Aug 2016

“The Other Half” US science podcast, published online, 4th Apr 2016

Media: Articles

Outlook for the weekend? Chilly, with a chance of confusion
A short article published in Significance, the magazine of the Royal Statistical Society and the American Statistical Association, discussing how statistics is important when making probabilistic forecasts. (October 2015)

Banking on better forecasts: the new maths of weather prediction
A short article on the Guardian website, discussing how we use computer simulators to make a weather forecast. Suitable for a mathematically literate audience. (January 2015)

Butterflies and Hurricanes: The Science of Weather Prediction
A general interest article written for the Corpus Christi College, Oxford, Alumni newsletter, The Sundial. (September 2014)

Predicting Predictability
A short article published in the Oxford Physics Department's newsletter (page 3), suitable for a general audience. (July 2012)