Contact Philippe Gachon:

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Adjunct Professor, Centre pour l’Étude et la Simulation du Climat à l’Échelle Régionale, Department of Earth and Atmospheric Sciences, University of Québec at Montreal, Montréal, Québec

Invited Professor, Institut National de la Recherche Scientifique, Eau-Terre-Environnement, University of Québec, Québec


Ph.D. in Environmental Sciences, University of Québec at Montréal (Thesis in numerical regional climate modeling and diagnostic analysis, 1999); Ph.D. Fellowships of Pétro-Canada and of University of Quebec at Montreal.

Post-Doctoral position: Visiting Fellowship in Canadian Government Laboratories (NSERC program), Maurice Lamontagne Institute, Department of Fisheries and Oceans, Mont-Joli, Québec (1999-2002).


Philippe Gachon

Research Scientist - Climate Scenarios and Downscaling Research

CURRENT S&T / RESEARCH - Contributing to Environment Canada’s mandate to improve information on the future climate, its extremes, and impacts as a basis for adaptive decision making in Canada

  • Climate scenarios development at high resolution
  • Statistical downscaling methods
  • Extremes and trends analysis: temperature (heat spells), precipitation (occurrence, intensity and duration of heavy precipitation events), winds and hydrologic variables (low/high flow)
  • Assessment of Regional Climate Models: reconstructed observed extremes and projected extreme climate events over Canada
  • Large/Mesoscale atmospheric dynamics and their interactions with regional climate variability and changes


Philippe Gachon is a Research Scientist at the Canadian Centre for Climate Modelling and Analysis, and Adjunct Professor at the University of Québec at Montréal (UQÀM, ESCER centre). Philippe Gachon obtained his PhD in 1999 in Environmental Sciences at UQÀM (Thesis' project on regional climate modeling and diagnostic analysis of storms), followed by a Post-Doctoral fellow at the Maurice Lamontagne Institute (Department of Fisheries and Oceans) on ocean-ice-atmosphere coupling problem between 1999 and 2002. He is currently the co-lead, with colleagues from INRS-ETE (Québec) and abroad, of the international FACE project to support vulnerable populations’ adaptation to climate variability and change in Canada, Morocco and Niger. His expertise encompasses statistical and dynamical downscaling, storm track and extreme analysis, and climate scenarios development at the regional scale. He works closely to develop tools to help improve human health, the sustainability and resilience of natural and human systems, and help assist with the transfer, integration and application of climate change information to adaptation knowledge and strategy.



Benyahya, L., P. Gachon, A. St-Hilaire and R. Laprise, 2014: Frequency analysis of seasonal extreme precipitation in southern Quebec (Canada): an evaluation of regional climate model with respect to gridded observed datasets, Hydrology Research, 45.1, 115-133, DOI:10.2166/nh.2013.066.

Roy, P., P. Gachon and R. Laprise, 2014: Sensitivity of seasonal precipitation extremes to model configuration of the Canadian Regional Climate Model over eastern Canada using historical simulations, Climate Dynamics (accepted, January 22nd, 2014) DOI: 10.1007/s00382-014-2066-z.


Bonsal, B. R., R. Aider, P. Gachon, and S. Lapp, 2013: An Assessment of Canadian Prairie Drought: Past, Present, and Future, Climate Dynamics, 41, 501-516, DOI 10.1007/s00382-012-1422-0.

Eum, H.-I., P. Gachon, and R. Laprise, 2013: Developing a likely climate scenario from multiple regional climate model simulations with an optimal weighting factor, Climate Dynamics (accepted, Dec. 7th, 2013), DOI 10.1007/s00382-013-2021-4.

Gaitan, C., W. Hsieh, A. Cannon and P. Gachon, 2013: Validation of linear and nonlinear downscaling methods in terms of weather and climate indices: Surface temperature in Ontario and Quebec, Atmosphere-Ocean.

Jeong, D.I., A. St-Hilaire, T.B.M.J. Ouarda, and P. Gachon, 2013: Projection of future daily precipitation series and extreme events by using a multi-site statistical downscaling model over the great Montréal area, Québec, Canada, Hydrology Research, 44.1, 147-168, DOI: 10.2166/nh.2012.183.

Jeong, D.I., A. St-Hilaire, T.B.M.J. Ouarda, and P. Gachon, 2013: Projection of Multi-site Daily Temperatures over the Montréal Area, Canada, Climate Research, 56, 261-280.

Khalili, M., V.T.V Nguyen, and P. Gachon, 2013: A statistical approach to multi-site downscaling of daily extreme temperature series, International Journal of Climatology 33: 15–32, DOI: 10.1002/joc.3402.

Sarr M.A., M. Zoromé, O. Seidou, C. Robin Bryant, and P. Gachon, 2013: Recent trends in selected extreme precipitation indices in Senegal-A change point approach, Journal of Hydrology, 505, 326-334, DOI: 10.1016/j.jhydrol.2013.09.032.


Eum, H.-I., P. Gachon, R. Laprise and T. Ouarda, 2012: Evaluation of regional climate model simulations versus gridded observed and regional reanalysis products using a combined weighting scheme, Climate Dynamics 38, Numbers 7-8, 1433-1457, DOI 10.1007/s00382-011-1149.

Jeong, D.I., A. St-Hilaire, T.B.M.J. Ouarda, and P. Gachon, 2012a: Comparison of transfer functions in a regression-based statistical downscaling model for daily temperature and precipitation over Canada, Stochastic Environmental Research & Risk Assessment, 26, 633-653, DOI: 10.1007/s00477-011-0523-3.

Jeong, D.I., A. St-Hilaire, T.B.M.J. Ouarda, and P. Gachon, 2012b: A multivariate multi-site statistical downscaling model for daily maximum and minimum temperatures, Climate Research, 54, 129–148, DOI: 10.3354/cr01106.

Jeong, D.I., A. St-Hilaire, T.B.M.J. Ouarda, and P. Gachon, 2012c: Multisite statistical downscaling model for daily precipitation combined by multivariate multiple linear regression and stochastic weather generator, Climatic Change, 114:567–591, DOI: 10.1007/s10584-012-0451-3.

Jeong, D.I., A. St-Hilaire, T.B.M.J. Ouarda, and P. Gachon, 2012d: CGCM3 predictors used for daily temperature and precipitation downscaling in southern Québec, Canada, Theoretical and Applied Climatology, 107 (3), 389-406, DOI: 10.1007/s00704-011-0490-0.

Jeong, D.I., A. St-Hilaire, T.B.M.J. Ouarda, and P. Gachon, 2012e: A Multi-site Statistical Downscaling Model for Daily Precipitation using Global Scale GCM Precipitation Outputs, International Journal of Climatology (in press), DOI: 10.1002/joc.3598.

Roy, P., P. Gachon and R. Laprise, 2012: Assessment of summer extremes and climate variability over the north-east of North America as simulated by the Canadian Regional Climate Model, International Journal of Climatology 32: 1615–1627, DOI: 10.1002/joc.2382.


Gachon, P., A.E. Harding, M. Radojevic, E. Pison and V-T-V. Nguyen, 2011: Downscaling Global and Regional Climate Models. Environment Canada, University of Toronto at Scarborough (CL@UT), Climate Impacts and Adaptation Science 2010, Issue 1: Planned Adaptation to Climate Change, ISSN 1927-7709, 19-49.

Hanesiak, J.M., R.E. Stewart, B.R. Bonsal, P. Harder, R. Lawford, R. Aider, B.D. Amiro, E. Atallah, A.G. Barr, T.A. Black, P. Bullock, J.C. Brimelow, R. Brown, H. Carmichael, C. Derksen, L.B. Flanagan, P. Gachon, H. Greene, J. Gyakum, W. Henson, T. Hogg, B. Kochtubajda, H. Leighton, C. Lin, Y. Luo, J.H. McCaughey, A. Meinert, A. Shabbar, K. Snelgrove, K. Szeto, A. Trishchenko, G. van der Kamp, S. Wang, L. Wen, E. Wheaton, C. Wielki, Y. Yang, S. Yirdaw, and T. Zha, 2011: Characterization and summary of the 1999-2005 Canadian Prairie drought, Atmosphere-Ocean 49, Issue 4, 421-452, DOI:10.1080/07055900.2011.626757.

Harding, A.E., P. Gachon and V-T-V. Nguyen, 2011: Replication of atmospheric oscillations, and their patterns, in predictors derived from Atmosphere–Ocean Global Climate Model output, International Journal of Climatology, 31: 1841–1847, DOI: 10.1002/joc.2191.

Khaliq, M.N., Ouarda, T.B.M.J., Gachon, P., and Sushama, L., 2011: Stochastic modeling of hot weather spells and their characteristics. Climate Research, 47, 187–199.


Khaliq, M.N., and Gachon, P., 2010: Pacific Decadal Oscillation climate variability and temporal pattern of winter flows in northwestern North America. Journal of Hydrometeorology 11, 917–933.


Khaliq MN, Ouarda TBMJ, Gachon P., Sushama, L, St-Hilaire A. 2009a: Identification of hydrological trends in the presence of short-term serial and cross correlations: review of the selected methods and their application to annual flow regimes of Canadian rivers. Journal of Hydrology 368, 117–130.

Khaliq MN, Ouarda TBMJ, and Gachon P. 2009b: Identification of temporal trends in annual and seasonal low flows occurring in Canadian rivers: the effect of short- and long-term persistence. Journal of Hydrology, 369, 183–197, doi:10.1016/j.jhydrol.2009.02.045.


Dibike, Y., P. Gachon, A. St-Hilaire, T. Ouarda, and VTV Nguyen, 2008: Uncertainty analysis of statistically downscaled temperature and precipitation regimes in northern Canada. Theoretical and Applied Climatology, 91, 149–170.

Hessami, M., P. Gachon, T. Ouarda, and A. St-Hilaire, 2008: Automated regression-based Statistical Downscaling Tool. Environmental Modelling & Software, 23, 813-834.

Hundecha, Y., A. St-Hilaire, T. Ouarda, S. El Adlouni, and P. Gachon, 2008: A non-stationary extreme value analysis for the assessment of changes in extreme wind speed over the Gulf of St-Lawrence, Canada. Journal of Applied Meteorology and Climatology, 47(11), 2745 – 2759, doi: 10.1175/2008JAMC1665.1.

Khaliq MN, Ouarda TBMJ, Gachon P., Sushama L. 2008: Temporal evolution of low flow regimes in Canadian rivers. Water Resources Research 44, W08436, doi:10.1029/2007WR006132.

Quilbé R., A.N. Rousseau, J-S. Moquet, N. Bao Trinh, Y. Dibike, P. Gachon, and D. Chaumont, 2008: Assessing the Effect of Climate Change on River Flow Using General Circulation Models and Hydrological Modelling: Application to the Chaudière River, Québec, Canada. Canadian Water Resources Journal 33, 73-94.


Gachon, P., and Y. Dibike, 2007: Temperature change signals in northern Canada: Convergence of statistical downscaling results using two driving GCMs. International Journal of Climatology 27, 1623-1641.

Gachon, P., 2007: Uncertainties in regional climate change scenarios. Expert Symposium on Climate Change: Modelling, Impacts, and Adaptations, Ed. S.Y. Liong, K.K. Phoon, and D.G. Toll, National University of Singapore, Singapore,17-19 December 2007, 45-54, ISBN:978-81-904438-3-8.

Khaliq, N., P. Gachon, A. St-Hilaire, T. Ouarda, and B. Bobée, 2007a: Southern Québec (Canada) Summer Heat Spells over the 1941-2000 Period: an Assessment of Observed Changes. Theoretical and Applied Climatology 88, 83–101.

Khaliq, N., T. Ouarda, A. St-Hilaire, and P. Gachon, 2007b: Bayesian change-point analysis of heat spell occurrences in Montreal, Canada. International Journal of climatology 27, 805-818.

Nguyen, TD., VTV. Nguyen, and P. Gachon, 2007: A spatial-temporal downscaling approach for construction of intensity-duration-frequency curves in consideration of GCM-based climate change scenarios, in Advances in Geosciences, Vol. 6: Hydrological Sciences”, N. Park et al. (Eds.), World Scientific Publishing Company, pp. 11-21.


Khaliq, N., T. Ouarda, P. Gachon, and B. Bobée, 2006: Frequency analysis of a sequence of dependent and/or non-stationary hydro-meteorological observations: a review. Journal of Hydrology 329, 534–552.

Nguyen, VTV., TD. Nguyen, and P. Gachon, 2006: On the linkage of large-scale climate variability with local characteristics of daily precipitation and temperature extremes: an evaluation of statistical downscaling methods. Advances in Geosciences (WSPC/SPI-B368) 4(16): 1-9.


Barrow, E., B. Maxwell and P. Gachon, 2004 : Climate Variability and Change in Canada: Past, Present and Future, Climate Change Impacts Scenarios Project, National Report, Environment Canada, Meteorological Service of Canada, Adaptation Impacts Research Group, Atmospheric and Climate Sciences Directorate publication, Canada, 114 pp, ISBN: 0-662-38497-0.

Saucier, F.J., S. Senneville, S. Prinsenberg, F. Roy, P. Gachon, D. Caya, and R. Laprise, 2004: Modeling the ice-ocean seasonal cycle in Hudson Bay, Foxe Basin and Hudson Strait, Canada. Climate Dynamics, 23, 303-326.


Gachon, P., R. Laprise, P. Zwack and F.J. Saucier, 2003: The effects of interactions between surface forcings in the development of a model-simulated polar low in Hudson Bay. Tellus A 55 (1), 61-87.

Gachon, P., and F.J. Saucier, 2003 : La modélisation du climat dans les mers intérieures du Canada : Baie d'Hudson et Golfe du Saint-Laurent. Naturaliste Canadien, vol. 127, n°2, 117-122.


Gachon, P., F.J. Saucier, and R. Laprise, 2002: Evaluation of summer-time near-surface temperature and wind fields over Hudson Bay in a regional atmospheric model. in Research activities in atmospheric and oceanic modelling, WMO-TD No. 1105, World Climate Research Program, CAS/JSC Working Group on Numerical Experimentation, Report n° 32, 5.13-5.14.

Senneville, S., F.J. Saucier, P. Gachon, R. Laprise, and D. Caya, 2002: Development of a coupled ice-ocean model of Hudson Bay. in Research activities in atmospheric and oceanic modelling, WMO-TD, No. 1105, World Climate Research Program, CAS/JSC Working Group on Numerical Experimentation, Report n° 32, 8.23-8.24.

Gachon, P. and F.J. Saucier, 2001: Sensitivity study of the effects of oceanic conditions in the Gulf of St. Lawrence (Québec, Canada) on wintertime atmospheric circulation, in Research activities in atmospheric and oceanic modelling, WMO-TD, Working Group on Numerical Experimentation (WGNE), Report n°31.

Gachon, P., F.J. Saucier, M. Faucher and R. Laprise, 2001: Development of an atmosphere-ocean-sea ice coupled regional model in the Gulf of St. Lawrence, in Research activities in atmospheric and oceanic modelling, WMO-TD, Working Group on Numerical Experimentation (WGNE), Report n°31.

Gachon, P., 2000 : La modélisation du climat - où en sommes nous ? VertigO - Revue en sciences de l'environnement, Vol 1 No 2, Septembre 2000.

Expertise Categories associated with this S&T Expert:

     Climate Change and Processes
          Adaptation and impacts
          Land Surface/Atmosphere Interactions
          Severe weather
          Trends and variability
     Climate Modelling
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