Sylvie Leroyer, PhD

Image Sylvie Leroyer
Research Scientist - Urban boundary-layer processes, surface processes

Urban meteorology specialist at the Environmental and Weather Numerical Prediction section (RPN-E) at the Meteorological Research Division.

My research includes High-resolution atmospheric modelling in urban areas, development of numerical systems for weather and environment prediction and for impact studies.

Current research and/or projects

Contribute to Environnement and climate Change Canada mandate to improve environmental numerical prediction, according to the following themes:

  • Urban Heat Island (ICU):  studies on the warm anomalies in urban areas in compariosn to natural surfaces. More specifically, we analyse the spatial heterogeneity from the city to the neighborhood scales, and the enegy exchanges at the surface.

  • bio-meteorology:  prediction of  thermal confort indicators, humidex, Universal thermal and climate index (UTCI), wet-bulb globe temperature (WBGT), Mean Radiant Temperature (MRT).

  • Atmospheric physics:  High-resolution modelling at high resolution of the surface-atmosphere interactions,  local atmospheric circulations such as sea and lake breezes, orographic and urban induced circulations, turbulence, surface radiation.

  • Impact studies: Evaluation of the impact of urban planning measures on heat mitigation in cities.

  • Extreme Weather: Effect of urban surfaces on extreme weather events such as heavy localized rainfalls and heat waves.

Key publications

Leroyer, S., Bélair, S., Souvanlasy, V., Vallée, M., Pellerin, S., & Sills, D. (2022). Summertime Assessment of an Urban-Scale Numerical Weather Prediction System for Toronto. Atmosphere13(7), 1030.  


Leroyer, S. (2022). Numerical Weather Prediction in Urban Areas for Climate Change Adaptation, feature article, spring bulletin, Canadian Society for Mechanical Engeneering. (link)


Leroyer, S., S. Bélair, N. Alavi, R. Muno-Alpizar, O. Nikiema, and I. Popadic, (2019). Influence des aménagements du tissu urbain sur la micrométéorologie et le confort thermique : Cas des villes de Montréal et Toronto. Rapport final de projet. Zenodo.

(projet financé par le Fonds Vert du gouvernement du Québec dans le cadre du plan d’action contre le changement climatique 2013-2020)


Baklanov A, Cárdenas B, Lee TC, Leroyer S, Masson V, Molina LT, Müller T, Ren C, Vogel FR, Voogt JA. (2020). Integrated urban services: Experience from four cities on different continents. Urban Climate, 32.  


Leroyer, S., S. Bélair, L. Spacek, I. Gultepe (2018).   Modelling of radiation-based heat stress indicators for urban high-resolution Numerical Weather Prediction, Urban Climate, 25, 64-81.  


Bélair, S., S. Leroyer, L. Spacek, N. Seino, and V. Souvanlasy., (2018). Role and impact of the urban Environment in a Numerical Forecast of an Intense Summertime Precipitation Event over Tokyo, J. Meteor. Soc. Japan., volume 96A, Pages 77-94.


Joe, P., and co-authors inc. S. Leroyer. (2018). The Pan-American Games Science Showcase Project,  Bulletin of American Meteorological Society (May).


Dehghan, A., Z. Mariani, S. Leroyer, P. Joe, D. Sills. S. Bélair (2018). Evaluation of Modeled Lake Breezes Using an Enhanced Observational Network in Southern Ontario: Case Studies, J. of meteorol and climatol. , 57, 7, 1511-1534. 


Leroyer S., Bélair S, Husain SZ, Mailhot J. (2014). Sub-kilometer numerical weather prediction in an urban coastal area: a case study over the Vancouver metropolitan area. Int. J. of Appl. Meteorol Climatol, 53:1433–1453.


Husain, S.Z., S. Bélair, and S. Leroyer (2014). Influence of Soil Moisture on Urban Microclimate and Surface-Layer Meteorology in Oklahoma City, In. J. of Appl. Meteorol and Climatol., 53, 83-98. DOI: 10.1175/JAMC-D-13-0156.1.


Leroyer, S., S. Bélair, J. Mailhot, and I. B. Strachan (2011). Microscale Numerical Prediction over Montreal with the Canadian External Urban Modeling System, J. appl. Meteorol and climatol., 50, 2410-2428. DOI:10.1175/JAMC-D-11-013.1.

Leroyer, S., J. Mailhot, S. Bélair, A. Lemonsu and I. B. Strachan (2010). Modeling the surface energy budget during the thawing period of the 2006 Montreal Urban Snow Experiment, J. appl. Meteorol and climatol., 49, 1, 68–84.

Leroyer, S., Calmet, I. and Mestayer, P. G. (2010). Urban Boundary Layer Simulations of Sea-Breeze over Marseille during the ESCOMPTE experiment, Int. J. Environment. And Pollution, 40, p. 109-122.

Research facility

2121, route Transcanadienne
Dorval, QC H9P 1J3



Other languages

English / French