Dr. William Merryfield

Chercheur - Application de modèles climatiques aux prévisions saisonnières à décennales
Environnement et Changement climatique Canada

Recherche et / ou projets en cours

Recherche, développement et analyse en lien avec les activités de prévision saisonnière et de modélisation climatique mondiale d’Environnement Canada

  • Prévision du climat à des échelles de temps variant entre un mois et une décennie
  • Développement de méthodes et de modèles améliorés pour la prévision climatique
  • Développement de produits et d’applications de prévision climatique
  • Analyse de simulations climatiques
  • Étude de l’influence des océans sur le climat

Activités professionnelles / intérêts

Membre, groupe de travail sur les prévisions saisonnières à interannuelles du Programme mondial de recherches sur le climat

Membre, comité directeur, réseau d’étude de l’évolution de la glace de mer et de la neige au Canada

Rédacteur adjoint, Atmosphere-Ocean

Prix et études

B.Sc. en physique, Université Stanford (États-Unis)

Ph.D. en sciences astrophysiques, planétaires et atmosphériques, Université du Colorado (États-Unis)

Environnement Canada, Mention d’excellence pour le travail d’équipe, le partenariat et la collaboration, 2013

Médaille du jubilé de diamant de la reine Elizabeth II, 2013

Principales publications

2015Klingaman, N. P., S. J. Woolnough, X. Jiang, D. Waliser, P. K. Xavier, J. Petch, M. Caian, C. Hannay, D. Kim, H.-Y. Ma, W. J. Merryfield, T. Miyakawa, M. Pritchard, J. A. Ridout, R. Roehrig, E. Shindo, F. Vitart, H. Wang, N. R. Cavanaugh, B. E. Mapes, A. Shelly, and G. J. Zhang, 2015: Vertical structure and physical processes of the Madden-Julian oscillation: Linking hindcast fidelity to simulated diabatic heating and moistening, Journal of Geophysical Research, accepted.Salimun, E., F. Tangang, L. Juneng, F. W. Zwiers and W. J. Merryfield, 2015: Skill evaluation of CanCM4 for seasonal climate forecast over Malaysia during the early and late winter monsoon periods, International Journal of Climatology, accepted.2014Fajber, R., A. H. Monahan and W. J. Merryfield, 2014: At what time of day do daily extreme near surface wind speeds occur?, Journal of Climate, 27, 4226-4244, doi:10.1175/JCLI-D-13-00286.1Kirtman, B., D. Min, J. M. Infanti, J. L. Kinter III, D. A. Paolino, Q. Zhang, H. van den Dool, S. Saha, M. Pena Mendez, E. Becker, P. Peng, P. Tripp, J. Huang, D. G. DeWitt, M. K. Tippett, A. G. Barnston, S. Li, S. D. Schubert, M. Rienecker, M. Suarez, Z. E. Li, J. Marshak, Y.-K. Lim, J. Tribbia, K. Pegion, W. J. Merryfield, B. Denis and E. F. Wood, 2014: The North American Multimodel Ensemble: Phase-1 seasonal-to-interannual prediction; Phase-2 toward developing intraseasonal prediction., Bulletin of the American Meteorological Society, 95, 585-601, doi:10.1175/BAMS-D-12-00050.1.2013Merryfield, W. J., W.-S. Lee, W. Wang, M. Chen, and A. Kumar, 2013: Multi-system seasonal predictions of Arctic sea ice, Geophysical Research Letters, 40, 1551-1556, doi:10.1002/grl.50317.Sigmond, M., J.C. Fyfe, G.M. Flato, V.V. Kharin and W. J. Merryfield, 2013: Seasonal forecast skill of Arctic sea ice area in a dynamical forecast system, Geophysical Research Letters, 40, 529-534, doi:10.1002/grl.50129.Boer, G. J., V. V. Kharin and W. J. Merryfield, 2013: Decadal predictability and forecast skill. Climate Dynamics, 41, 1817-1833, doi:10.1007/s00382-013-1705-0.Merryfield, W. J., W.-S. Lee, G. J. Boer, V. V. Kharin, J. F. Scinocca, G. M. Flato, R. S. Ajayamohan, J. C. Fyfe, Y. Tang, and S. Polavarapu, 2013: The Canadian Seasonal to Interannual Prediction System. Part I: Models and Initialization, Monthly Weather Review, 141, 2910-2945, doi:10.1175/MWR-D-12-00216.1.2012Smith, D. M., A. A. Scaife, G. J. Boer, M. Caian, F. J. Doblas-Reyes, V. Guemas, E. Hawkins, W. Hazeleger, L. Hermanson, C. K. Ho, M. Ishii, V. Kharin, M. Kimoto, B. Kirtman, J. Lean, D. Matei, W. J. Merryfield, W. A. Müller, H. Pohlmann, A. Rosati, B. Wouters and K. Wyser, 2012: Real-time multi-model decadal climate predictions. Climate Dynamics, 41, 2875-2888, 10.1007/s00382-012-1600-0.Kharin, V. V., G. J. Boer, W. J. Merryfield, J. F. Scinocca, and W.-S. Lee, 2012: Statistical adjustment of decadal predictions in a changing climate. Geophysical Research Letters, 39, L19705, doi:10.1029/2012GL052647.Goddard, L., A. Kumar, A. Solomon, D. Smith, G. Boer, P. Gonzalez, C. Deser, S. Mason, B. Kirtman, R. Msadek, R. Sutton, E. Hawkins, T. Fricker, V. Kharin, W. Merryfield, G. Hegerl, C. Ferro, D. Stephenson, G.A. Meehl, T. Stockdale, R. Burgman, A. Greene, Y. Kushnir, M. Newman, J. Carton, I. Fukumori, D. Vimont and T. Delworth, 2012: A verification framework for interannual-to-decadal predictions experiments. Climate Dynamics, 40, 245-272, doi:10.1007/s00382-012-1481-2.Drewitt, G., A. A. Berg, W. J. Merryfield and W.-S. Lee, 2012: Effect of realistic soil moisture initialization on the Canadian CanCM3 seasonal forecast model. Atmosphere-Ocean, 50, 466-474. doi:10.1080/07055900.2012.722910.Saenko, O. A., X. Zhai, W. Merryfield and W. Lee, 2012: The combined effect of tidally and eddy driven diapycnal mixing on the large-scale ocean circulation. Journal of Physical Oceanography, 42, 526-538. doi: 10.1175/JPO-D-11-0122.1.Finnis, J., W. W. Hsieh, H. Lin and W. J. Merryfield, 2012: Nonlinear post-processing of numerical seasonal climate forecasts. Atmosphere-Ocean, 50, 207-218. doi:10.1080/07055900.2012.667388.2011Fyfe, J. C., W. J. Merryfield, V. Kharin, G.J. Boer, W.-S. Lee and K. von Salzen, 2011: Skillful predictions of decadal trends in global mean surface temperature. Geophysical Research Letters, 38, L22801, doi:10.1029/2011GL049508.Foreman, M. G. G., B. Pal and W. J. Merryfield, 2011: Trends in upwelling and downwelling winds along the British Columbia shelf. Journal of Geophysical Research, 116, C10023. doi:10.1029/2011JC006995.Alavi, N., G. Drewitt, A. A. Berg, and W. J. Merryfield, 2011: Soil moisture initialization effects in the CCCma AGCM3: Relationship of seasonal climate forecast error to uncertainty in soil moisture initializations. Atmosphere-Ocean, 49, 179-188, doi: 10.1080/07055900.2011.608422.Lienert, F., J. C. Fyfe and W. J. Merryfield, 2011: Do climate models capture the tropical influences on North Pacific sea surface temperature variability? Journal of Climate, 24, 6203-6209, doi: 10.1175/JCLI-D-11-00205.1 .Koster, R. D., S. P. P. Mahanama,, T. J. Yamada, G. Balsamo, A. A. Berg, M. Boisserie, P. A. Dirmeyer, F. J. Doblas-Reyes, G. Drewitt, C. T. Gordon, Z. Guo, J.-H. Jeong, W.-S. Lee, Z. Li,, L. Luo, S. Malyshev, W. J. Merryfield, S. I. Seneviratne, T. Stanelle, B. J. J. M. van den Hurk, F. Vitart, and E. F. Wood, 2011: The second phase of the Global Land-Atmosphere Coupling Experiment: Soil moisture contributions to subseasonal forecast skill. Journal of Hydrometeorology, 12, 805-822. doi: 10.1175/2011JHM1365.1Arora, V., J. Scinocca, G. Boer, J. Christian, K. L. Denman, G. Flato, V. Kharin, W. Lee, W. Merryfield, 2011: Carbon emission limits required to satisfy future representative concentration pathways of greenhouse gases. Geophysical Research Letters, 38, L05805, doi:10.1029/2010GL046270.Denissenkov, P. A., and W. J. Merryfield, 2011: Thermohaline mixing: Does it really govern the atmospheric chemical composition of low-mass red giants? Astrophysical Journal Letters, 727, L8.Gillett, N. P., V. Arora, K. Zickfeld, S. Marshall, and W. J. Merryfield, 2011: Ongoing climate change following a complete cessation of carbon dioxide emissions, Nature Geoscience, 4, 83-87, doi:10.1038/NGEO1047.2010Merryfield, W. J., W.-S. Lee, G. J. Boer, V. V. Kharin, B. Pal, J. F. Scinocca and G. M. Flato, 2010: The first Coupled Historical Forecasting Project (CHFP1). Atmosphere-Ocean, 48, 263-283.Bakalian, F., H. Ritchie, K. Thompson and W. Merryfield, 2010: Exploring atmosphere-ocean coupling using principal component and redundancy analysis. Journal of Climate, 23, 4926-4943.Christian, J. R., V. K. Arora, G. J. Boer, C. Curry, K. Zahariev, K. Denman, G. Flato, W. Lee, W. Merryfield, N. Roulet, and J. Scinocca, 2010: The global carbon cycle in the CCCma earth system model CanESM1: preindustrial control simulation. Journal of Geophysical Research (Biogeosciences), 115, G03014, doi:10.1029/2008JG000920.Scott, R. B., B. K. Arbic, E. P. Chassignet, A. C. Coward, M. Maltrud, W. J. Merryfield, A. Srinivasan, A. Varghese, 2010: Total kinetic energy in four global eddying ocean circulation models and over 5000 current meter records. Ocean Modelling, 32, 157-169, doi:10.1016/j.ocemod.2010.01.005.Ajayamohan., R. S., W. J. Merryfield, and V. V. Kharin, 2010: Increasing trend of synoptic activity and its relationship with extreme rain events over central India. Journal of Climate, 23, 1004-1013.Koster, R. D., S. P. P. Mahanama,, T. J. Yamada, G. Balsamo, A. A. Berg, M. Boisserie, P. A. Dirmeyer, F. J. Doblas-Reyes, G. Drewitt, C. T. Gordon, Z. Guo, J.-H. Jeong, D. M. Lawrence, W.-S. Lee, Z. Li,, L. Luo, S. Malyshev, W. J. Merryfield, S. I. Seneviratne, T. Stanelle, B. J. J. M. van den Hurk, F. Vitart, and E. F. Wood, 2010: Contribution of land surface initialization to subseasonal forecast skill: First results from a multi-model experiment. Geophysical Research Letters, 37, L02402. doi:10.1029/2009GL041677.2009Arora, V. K., G. J. Boer, J. R. Christian, C. L. Curry, K. L. Denman, K. Zahariev, G. M. Flato, J. F. Scinocca, W. J. Merryfield, W. G. Lee 2009: The effect of terrestrial photosynthesis down-regulation on the 20th century carbon budget simulated with the CCCma Earth System Model, Journal of Climate, 22, 6066-6088.Yu, B., G. J. Boer, F. W. Zwiers and W. J. Merryfield, 2009: Covariability of SST and surface heat fluxes in reanalyses and CMIP3 climate models. Climate Dynamics, 22, 589-605, doi:10.1007/s00382-009-0669-6.Merryfield, W. J., B. Pal, and M. G. G. Foreman, 2009: Projected future changes in surface marine winds off the west coast of Canada. Journal of Geophysical Research, 114, C06008, doi:10.1029/2008JC005123.2008 and earlierMerryfield, W. J., M. M. Holland and A. H. Monahan, 2008: Multiple equilibria and abrupt transitions in Arctic summer sea ice extent. AGU Monograph "Arctic Sea Ice Decline: Observations, Projections, Mechanisms, and Implications", Geophys. Monogr. Ser., vol. 180, edited by E. T. DeWeaver, C. M. Bitz, and L.-B. Tremblay, pp. 151-174, AGU, Washington, D. C.

Merryfield, W. J. and R. B. Scott, 2007: Bathymetric influence on mean currents in two high-resolution near-global ocean models. Ocean Modelling, 16, 76-94, doi:10.1016/j.ocemod.2006.07.005

Saenko, O. A. and W. J. Merryfield, 2006: Vertical partition of ocean heat transport in isothermal coordinates. Geophysical Research Letters, 33, L01606, doi:10.1029/2005GL024902.Merryfield, W. J., 2006: Changes to ENSO under CO2 doubling in a multi-model ensemble. Journal of Climate, 19, 4009-4027.Morell, J. M., J. C. Corredor, and W. J. Merryfield, 2006: Thermohaline staircases in a Caribbean eddy and mechanisms for staircase formation. Deep-Sea Research II, Proceedings of the IAPSO/SCOR Conference on Ocean Mixing, 53, 128-139.Merryfield, W. J., 2005: Dependence of differential mixing on N and Rρ. Journal of Physical Oceanography, 35, 991-1003. 

Merryfield, W. J., 2005: Ocean mixing in 10 steps. Science, 308, 641-642 (perspective article).

Saenko, O. A., and W. J. Merryfield, 2005: On the effect of topographically enhanced mixing on the global ocean circulation. Journal of Physical Oceanography, 35, 826-834.Merryfield, W. J., and G. J. Boer, 2005: Variability of upper Pacific Ocean overturning in a coupled climate model. Journal of Climate, 18, 666-683.Gargett, A. E., W. J. Merryfield, and G. Holloway, 2003: Direct numerical simulation of differential scalar diffusion in three-dimensional stratified turbulence. Journal of Physical Oceanography, 33, 1758-1782.Merryfield, W. J., and G. Holloway, 2003: Application of an accurate advection algorithm to sea-ice modelling. Ocean Modelling, 5, 1-15.Merryfield, W. J., 2002: Intrusions in double-diffusively stable Arctic waters: Evidence for differential mixing? Journal of Physical Oceanography, 32, 1452-1459.Merryfield, W. J., and G. Holloway, 2002: Predictability of quasi-geostrophic turbulence. Journal of Fluid Mechanics, 465, 191-212.Merryfield, W. J., Cummins, P. F. and G. Holloway, 2001: Equilibrium statistical mechanics of barotropic flow over finite topography, Journal of Physical Oceanography, 31, 1880-1890.Merryfield, W. J., 2000: Origin of thermohaline staircases. Journal of Physical Oceanography, 30,1046-1068.Merryfield, W. J., G. Holloway, and A. E. Gargett, 1999: A global ocean model with double-diffusive mixing, Journal of Physical Oceanography, 29, 1124-1142.Merryfield, W. J., and G. Holloway, 1999: Eddy fluxes and topography in stratified quasi-geostrophic models, Journal of Fluid Mechanics, 380, 59-80.Merryfield, W. J., G. Holloway, and A. E. Gargett, 1998: Differential transport of heat and salt by weak stratified turbulence, Geophysical Research Letters, 25, 2773-2776.Merryfield, W. J., 1998: Effects of stratification on quasi-geostrophic inviscid equilibria. Journal of Fluid Mechanics, 354, 345-356.Merryfield, W. J., and G. Holloway, 1997: Topographic stress parameterization in a quasi-geostrophic barotropic model. Journal of Fluid Mechanics, 341, 1-18.Merryfield, W. J., and G. Holloway, 1996: Inviscid quasi-geostrophic flow over topography: testing statistical mechanical theory. Journal of Fluid Mechanics, 30