Professor Peter Jan van Leeuwen

Professor of Data Assimilation

Web Pages:

Group: http://www.met.rdg.ac.uk/~darc

My research: http://www.met.rdg.ac.uk/~xv901096

Responsibilities:

Interim Director of the National Centre for Earth Observation (NCEO)

Professor of Data Assimilation

Research Interests:

  • Nonlinear data assimilation
  • Geophysical fluid dynamics
  • Interaction thermohaline and wind-driven ocean circulation
  • Perturbation theory

Research Projects:

  • Ensemble data-assimilation system development (SANGOMA) In the EU-funded project SANGOMA we develop new nonlinear ensemble data-assimilation methods and implement them in existing ensemble data-assimilation software packages for use by the European oceanographic community.
  • Particle filters for climate models. We explore the Equivalent-Weights Partticle Filter in HadCM3, a climate model with about a million variables.
  • Localization in Particle Filters. We are exploring using Ensemble Kalman Filter-like proposals with localisation in particle filters.
  • Particle filters with 4DVar as proposal density.We are exploring ensembles of 4D-Var as particles in a particle filter, using on the ensemble of 4D-Var system presently operational at the ECMWF.
  • Comparing Particle filtering and MCMC in geophysical systems: exploring the proposal density.The idea is to build a particle filter for highly nonlinear high-dimensional systems and test the posterior pdf representation with MCMC methods. We will also try to make the MCMC methods more efficient exploring our ideas from particle filtering.
  • Efficient nonlinear data-assimilation methods for parameter and paremeterisation estimation.Using model tentencies after data-assimilation with the Ensemble Kalman Smoother and a Particle Smoother we will try to find new nonlinear methods for parametyer and parameterisation estimation.
  • Hybrid scheme's for next generation data assimilations. We are exploring 4 hybrid data-assimilation scheme's between Ensemble Kalman Filters, Particle filters and 4D-Var and compare their merits and problems using the 1-D convective shallow-water model developed by George Craig (Munich).
  • Particle filtering with square-root Kalman filters as proposal.Exploring ideas from the Auxiliary Particle Filter and square-root Ensemble Kalman Filters to come up with new efficient nonlinear data-assimilation schemes for high-dimensional systems.
  • Hybrid algorithms of ensemble transform and importance sampling for nonlinear observations.

Postdoctoral & graduate student supervision

  • Melanie Ades PDRA working on efficient particle filters and MCMC.
  • Phil Browne PDRA working on efficient particle filters for climate models, specifically HadCM3.
  • Javier Amezcua PDRA working on 4DVar ensemble members as particles in particle filters, with ECMWF.
  • David Livings PDRA working on localisation in particle filters.
  • Sanita Vetra Carvalho PDRA working on ensemble data-assimilation framework for oceanographic applications in SANGOMA.
  • Shinya Nakano Visitor from Institute of Mathematical Statistics, Tokyo, working on hybrids of ensemble transform and importance sampling methods.
  • Matthew Lang PhD student working on nonlinear methods for parameter and parameterisation estimation.
  • Michael Goodliff PhD student working on hybrid EnKF,Particle Filter and 4DVar methods.
  • John de Vries PhD student working on auxiliary particle filters combined with ensemble square-root methods.

Other interests

  • Information transfer in complex systems.

For most recent publication list see here.

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Recent Publications:

Jump to: 2014 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 | 2005
Number of items: 28.

2014

Vaughan, G., Methven, J., Anderson, D., Antonescu, B., Baker, L., Baker, T. P., Ballard, S. P., Bower, K. N., Brown, P. R. A., Chagnon, J., Choularton, T. W., Chylik, J., Connolly, P. J., Cook, P. A., Cotton, R. J., Crosier, J., Dearden, C., Dorsey, J. R., Frame, T. H. A., Gallagher, M. W., Goodliff, M., Gray, S. L., Harvey, B. J., Knippertz, P., Lean, H. W., Li, D., Lloyd, G., Martinez-Alvarado, O., Nicol, J., Norris, J., Öström, E., Owen, J., Parker, D. J., Plant, R. S., Renfrew, I. A., Roberts, N. M., Rosenberg, P., Rudd, A. C., Schultz, D. M., Taylor, J. P., Trzeciak, T., Tubbs, R., Vance, A. K., Van Leeuwen, P. J., Wellpott, A. and Woolley, A. (2014) Cloud banding and winds in intense European cyclones: results from the DIAMET project. Bulletin of the American Meteorological Society. ISSN 1520-0477 (In Press)

2013

Van Leeuwen, P. J. and Ades, M. (2013) Efficient fully nonlinear data assimilation for geophysical fluid dynamics. Computers & Geosciences, 55. pp. 16-27. ISSN 0098-3004 doi: 10.1016/j.cageo.2012.04.015

Fowler, A. and Van Leeuwen, P. J. (2013) Observation impact in data assimilation: the effect of non-Gaussian observation error. Tellus A. Dynamic meteorology and oceanography, 65. 20035. ISSN 1600-0870 doi: 10.3402/tellusa.v65i0.20035

Ades, M. and Van Leeuwen, P. J. (2013) An exploration of the equivalent weights particle filter. Quarterly Journal of the Royal Meteorological Society, 139 (672 part A). pp. 820-840. ISSN 1477-870X doi: 10.1002/qj.1995

Moodey, A. J. F., Lawless, A. S., Potthast, R. W. E. and Van Leeuwen, P. J. (2013) Nonlinear error dynamics for cycled data assimilation methods. Inverse Problems, 29 (2). 025002. ISSN 0266-5611 doi: 10.1088/0266-5611/29/2/025002

2012

Kramer, W., Dijkstra, H. A., Pierini, S. and van Leeuwen, P. J. (2012) Measuring the impact of observations on the predictability of the Kuroshio Extension in a shallow-water model. Journal of Physical Oceanography, 42 (1). pp. 3-17. ISSN 0022-3670 doi: 10.1175/JPO-D-11-014.1

Fowler, A. and Van Leeuwen, P. (2012) Measures of observation impact in non-Gaussian data assimilation. Tellus A, 64. 17192. ISSN 1600-0870 doi: 10.3402/tellusa.v64i0.17192

2011

van Leeuwen, P. (2011) Efficient non-linear data assimilation in geophysical fluid dynamics. Computers & Fluids, 46 (1). pp. 52-58. ISSN 0045-7930 doi: 10.1016/j.compfluid.2010.11.011

2010

Ridderinkhof, H., van der Werf, P. M., Ullgren, J. E., van Aken, H. M., Van Leeuwen, P. J. and de Ruijter, W. P. M. (2010) Seasonal and interannual variability in the Mozambique Channel from moored current observations. Journal of Geophysical Research, 115 (C6). C06010. ISSN 0148-0227 doi: 10.1029/2009JC005619

van der Werf, P. M., Van Leeuwen, P. J., Ridderinkhof, H. and de Ruijter, W. P. M. (2010) Comparison between observations and models of the Mozambique Channel transport: Seasonal cycle and eddy frequencies. Journal of Geophysical Research, 115 (C2). C02002. ISSN 0148-0227 doi: 10.1029/2009JC005633

van Sebille, E., Van Leeuwen, P. J., Biastoch, A. and de Ruijter, W. P.M. (2010) Flux comparison of Eulerian and Lagrangian estimates of Agulhas leakage: A case study using a numerical model. Deep Sea Research Part I: Oceanographic Research Papers, 57 (3). pp. 319-327. ISSN 0967-0637 doi: 10.1016/j.dsr.2009.12.006

van Leeuwen, P. J. (2010) Nonlinear data assimilation in geosciences: an extremely efficient particle filter. Quarterly Journal of the Royal Meteorological Society, 136 Part B (653). pp. 1991-1999. ISSN 1477-870X doi: 10.1002/qj.699

van Sebille, E., Van Leeuwen, P. J., Biastoch, A. and de Ruijter, W. P. M. (2010) On the fast decay of Agulhas rings. Journal of Geophysical Research, 115 (C3). C03010. ISSN 0148-0227 doi: 10.1029/2009JC005585

2009

Van Leeuwen, P. J. (2009) Particle filtering in geophysical systems. Monthly Weather Review, 137 (12). pp. 4089-4114. ISSN 0027-0644 doi: 10.1175/2009MWR2835.1

van der Werf, P. M., Schouten, M. W., Van Leeuwen, P. J., Ridderinkhof, H. and de Ruijter, W. P. M. (2009) Observation and origin of an interannual salinity anomaly in the Mozambique Channel. Journal of Geophysical Research, 114 (C3). C03017. ISSN 0148-0227 doi: 10.1029/2008JC004911

van Sebille, E., Biastoch, A., Van Leeuwen, P. J. and de Ruijter, W. P. M. (2009) A weaker Agulhas Current leads to more Agulhas leakage. Geophysical Research Letters, 36 (3). L03601. ISSN 0094-8276 doi: 10.1029/2008GL036614

van Sebille, E., Van Leeuwen, P. J., Biastoch, A., Barron, C.N. and de Ruijter, W.P.M. (2009) Lagrangian validation of numerical drifter trajectories using drifting buoys: Application to the Agulhas system. Ocean Modelling, 29 (4). pp. 269-276. ISSN 1463-5003 doi: 10.1016/j.ocemod.2009.05.005

Van Leeuwen, P. J. and de Ruijter, W. P. M. (2009) On the steadiness of separating meandering currents. Journal of Physical Oceanography, 39 (2). pp. 437-448. ISSN 0022-3670 doi: 10.1175/2008JPO3869.1

Van Sebille, E., Barron, C.N., biastoch, A., Van Leeuwen, P. J., Vossepoel, F.C. and De Ruijter, W.P.M. (2009) Relating Agulhas leakage to the Agulhas Current retroflection location. Ocean Science, 5 (4). pp. 511-521. ISSN 1812-0784 doi: 10.5194/os-5-511-2009

De Steur, L. and Van Leeuwen, P. J. (2009) The influence of bottom topography on the decay of modeled Agulhas rings. Deep Sea Research Part I: Oceanographic Research Papers , 56 (4). 471-494 . ISSN 0967-0637 doi: 10.1016/j.dsr.2008.11.009

2008

Sterl, A., Severijns, C., Dijkstra, H., Hazeleger, W., Jan van Oldenborgh, G., van den Broeke, M., Burgers, G., van den Hurk, B., Van Leeuwen, P. J. and van Velthoven, P. (2008) When can we expect extremely high surface temperatures? Geophysical Research Letters, 35 (14). L14703. ISSN 0094-8276 doi: 10.1029/2008GL034071

2007

van Sebille , E. and van Leeuwen, P. J. (2007) Fast northward energy transfer in the Atlantic due to Agulhas rings. Journal of Physical Oceanography, 37 (9). pp. 2305-2315. ISSN 0022-3670 doi: 10.1175/JPO3108.1

Van Leeuwen, P. J. (2007) The propagation mechanism of a vortex on the β plane. Journal of Physical Oceanography, 37 (9). pp. 2316-2330. ISSN 0022-3670 doi: 10.1175/JPO3107.1

Palastanga, V., Van Leeuwen, P. J., Schouten, M. W. and de Ruijter, W. P. M. (2007) Flow structure and variability in the subtropical Indian Ocean: Instability of the South Indian Ocean Countercurrent. Journal of Geophysical Research, 112 (C1). C01001. ISSN 0148-0227 doi: 10.1029/2005JC003395

Vossepoel, F. C. and Van Leeuwen, P. J. (2007) Parameter estimation using a particle method: inferring mixing coefficients from sea level observations. Monthly Weather Review, 135 (3). pp. 1006-1020. ISSN 0027-0644 doi: 10.1175/MWR3328.1

2006

de Ruijter, W. P. M., Brummer, G. -J. A., Drijfhout, S. S., Lutjeharms, J. R. E., Peeters, F., Ridderinkhof, H., van Aken, H. and Van Leeuwen, P. J. (2006) Observations of the inter-ocean exchange around South Africa. EOS transactions, 87 (9). p. 97. ISSN 0096-3941 doi: 10.1029/2006EO090002

Palastanga, V., Van Leeuwen, P. J. and de Ruijter, W. P. M. (2006) A link between low-frequency mesoscale eddy variability around Madagascar and the large-scale Indian Ocean variability. Journal of Geophysical Research, 111 (C9). C09029. ISSN 0148-0227 doi: 10.1029/2005JC003081

2005

Brasseur, P., Bahurel, P., Bertino, L., Birol, F., Brankart, J.-M., Ferry, N., Losa, S., Remy, E., Schröter, J., Skachko, S., Testut, C.-E., Tranchant, B., Van Leeuwen, P. J. and Verron, J. (2005) Data assimilation for marine monitoring and prediction: The MERCATOR operational assimilation systems and the MERSEA developments. Quarterly Journal of the Royal Meteorological Society, 131 (613). pp. 3561-3582. ISSN 1477-870X doi: 10.1256/qj.05.142

This list was generated on Wed Oct 29 22:18:11 2014 GMT.

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p.j.vanleeuwen@reading.ac.uk

Office: 1U14

Extension: 5578

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