Patrick Laloyaux is a research scientist working to improve global numerical weather prediction. Data assimilation is the very best way to make a forecast out of a numerical model and a set of observations. His expertise includes coupled atmosphere-ocean assimilation, bias correction of model and satellite observations, atmospheric 4D-Var and climate reanalysis.
- Coupled atmosphere-ocean assimilation
- Earth system reanalysis
- Variational and ensemble assimilation methods
- Climate change
- Software architecture
- Numerical optimisation
Trained as an applied mathematician, he has expertise in optimisation methods for variational problems and in ensemble Kalman filters. He obtained his PhD from the University of Namur (Belgium) conducted in partnership with the European Centre for Research and Advanced Training in Scientific Computation (CERFACS, France). During his PhD, he developed new preconditioning and gradient-free techniques for solving variational problems. He was also a teaching assistant giving tutorials (220 hours/year) to undergraduate and graduate students in programming, scientific computation and numerical optimization.
- 2024
- (December 2024) An update on AI–DOP: skilful weather forecasts produced directly from observations, ECMWF Newsletter n. 182, pp. 15-18. DOI: 10.21957/tmi6y913dc
- 2021
- Richard Forbes, Patrick Laloyaux, Mark John Rodwell (October 2021) IFS upgrade improves moist physics and use of satellite observations, ECMWF Newsletter, issue 169, pp. 17-24. DOI: 10.21957/m3805gf17r
- Inna Polichtchouk, Peter Bechtold, Massimo Bonavita, Richard Forbes, Sean Healy, Robin Hogan, Patrick Laloyaux, Michael Rennie, Timothy Stockdale, Nils Wedi, Michail Diamantakis, Johannes Flemming, Stephen English, Lars Isaksen, Filip Vána, Sonja Gisinger, Nicholas Byrne (January 2021) Stratospheric modelling and assimilation, ECMWF Technical Memoranda n. 877. DOI: 10.21957/25hegfoq
- (April 2021) Data assimilation or machine learning? , ECMWF Newsletter, pp. 17-22. DOI: 10.21957/ut51mb7c39
- 2020
- Patrick Laloyaux, Massimo Bonavita (April 2020) Improving the handling of model bias in data assimilation, ECMWF Newsletter, issue 163, pp. 18-22. DOI: 10.21957/pl881qs63d
- 2018
- (May 2018) CERA-20C: A Coupled Reanalysis of the Twentieth Century, Journal of Advances in Modeling Earth Systems. DOI: 10.1029/2018ms001273
- Patrick Laloyaux, Sergey Frolov, Benjamin Ménétrier, Massimo Bonavita (October 2018) Implicit and explicit cross-correlations in coupled data assimilation, Quarterly Journal of the Royal Meteorological Society. DOI: 10.1002/qj.3373
- Hans Hersbach, Patricia de Rosnay, Bill Bell, Dinand Schepers, Adrian Simmons, Cornel Soci, Saleh Abdalla, Magdalena A. Balmaseda, Gianpaolo Balsamo, Peter Bechtold, P. Berrisford, Jean Bidlot, de Boisséson E., Massimo Bonavita, Browne P., Roberto Buizza, Per Dahlgren, Dick Dee, Rossana Dragani, Michail Diamantakis, Johannes Flemming, Richard Forbes, Alan Geer, Thomas Haiden, Elias Hólm, L. Haimberger, Robin Hogan, Andras Horanyi, Janiskova M., Patrick Laloyaux, Philippe Lopez, Joaquin Muñoz-Sabater, C. Peubey, Raluca Radu, David Richardson, Jean-Noel THEPAUT, Frederic Vitart, Yang X, Ervin Zsoter, Hao Zuo (December 2018) Operational global reanalysis: progress, future directions and synergies with NWP, ERA Report Series n. 27. DOI: 10.21957/tkic6g3wm
- Patrick Laloyaux, Frolov S., B. Ménétrier, Massimo Bonavita (August 2018) Implicit and explicit cross-correlations in coupled data assimilation, ECMWF Technical Memoranda n. 827. DOI: 10.21957/hpbwlimdj
- 2017
- Massimo Bonavita, Y. Trémolet, Elias Hólm, S. T. K. Lang, Marcin Chrust, Marta Janiskova, Philippe Lopez, Patrick Laloyaux, Patricia de Rosnay, Mike Fisher, M. Hamrud, Stephen English (February 2017) A Strategy for Data Assimilation, ECMWF Technical Memoranda n. 800. DOI: 10.21957/tx1epjd2p
- 2016
- (March 2016) Impact of Scatterometer Surface Wind Data in the ECMWF Coupled Assimilation System, Monthly Weather Review. DOI: 10.1175/mwr-d-15-0084.1
- (January 2016) A coupled data assimilation system for climate reanalysis, Quarterly Journal of the Royal Meteorological Society. DOI: 10.1002/qj.2629
- (June 2016) ERA-20C: An Atmospheric Reanalysis of the Twentieth Century, Journal of Climate. DOI: 10.1175/jcli-d-15-0556.1
- 2015
- (November 2015) Origin and Impact of Initialization Shocks in Coupled Atmosphere–Ocean Forecasts*, Monthly Weather Review. DOI: 10.1175/mwr-d-15-0076.1