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Alain Royer


Regular member

Department of Applied Geomatics, Université de Sherbrooke

2500, boul. de l'Université
Université de Sherbrooke
Quebec, Canada
J1K 2R1

819.821.8000 #62286



Research Themes

  • Development of environmental monitoring methods
  • Extraction of physical parameters of snow cover, vegetation and soil by satellite
  • Physics of remote sensing measurements, fusion of visible, thermal infrared and microwave data
  • Spatial geophysics of northern environments in a changing climate
  • Study of atmospheric aerosols and monitoring of air quality by remote sensing

CEN Students / Postdoctoral fellows

Kramer, Daniel (Doctorate - Codirector). Temporal and spatial snow characterization using high-resolution modeling, microwave remote sensing and UAVs in the Canadian High Arctic.

Sasseville, Vincent (Doctorate - Codirector). Implementation of a habitat quality index for the Peary caribou using snow geophysical properties retrieved from satellite remote sensing and modeling.

Vargel, Céline (Doctorate). Snow parameterization and microwave modelling: investigation of the climate change impact on snow dynamic processes in the Arctic, sub-Arctic and Antarctic environments.


Recent CEN theses

Larue, Fanny , 2018 (Doctorate). Development of a system to assimilate microwave satellite observations into a snow model for hydrological forecasting.

Mavrovic, Alex , 2018 (Master). Dielectric characterization of vegetation and soil at L-band (1.4 GHz) .

Prince, Michaël , 2018 (Master). Northern regions freeze/thaw cycles analysis with L-band passive microwaves remote sensing .

Saint-Jean Rondeau, Olivier , 2018 (Master). Modeling of microwave emission related to physical and microstructural properties of snow.

Busseau, Bruno-Charles , 2017 (Master). Analysis of snow-vegetation interactions in the low Arctic-Subarctic transition zone (Nunavik).

Marchand, Nicolas , 2017 (Doctorate). Surface ground temperature survey in arctic permafrost regions by using remote sensing data assimilated in the canadian landscape surface scheme (CLASS).

Pomerleau, Patrick , 2017 (Master). Design of an automatic device for characterizing the ice by use of a continuous emission radar.

Ouellet, Félix , 2016 (Master - Codirection). Spatialization of the SNOWPACK Snow Model for the Canadian Arctic to assess Peary caribou winter grazing conditions.


Scientific communications

Mavrovic, A., Madore, J.-B., Langlois, A., Royer, A., Roy, A.R., 2020. Snow liquid water content measurement using an open-ended coaxial probe (OECP). Cold Regions Science and Technology, 171, 102958. DOI: 10.1016/j.coldregions.2019.102958.

Roy, A.R., Toose, P., Mavrovic, A., Pappas, C., Royer, A., Derksen, C., Berg, A., Rowlandson, T., El-Amine, M., Barr, A., Black, A., Langlois, A., Sonnentag, O., 2020. L-Band response to freeze/thaw in a boreal forest stand from ground- and tower-based radiometer observations. Remote Sensing of Environment, 273, 111542. DOI: 10.1016/j.rse.2019.111542.

Vargel, C., Royer, A., Saint-Jean Rondeau, O., Picard, G., Roy, A.R., Sasseville, V., Langlois, A., 2020. Arctic and subarctic snow microstructure analysis for microwave brightness temperature simulations. Remote Sensing of Environment, 242, 11754. DOI: 10.1016/j.rse.2020.111754.

Prince, M., Roy, A.R., Royer, A., Langlois, A., 2019. Timing and spatial variability of fall soil freezing in boreal forest and its effect on SMAP L-band radiometer measurements. Remote Sensing of Environment, 231, 111230. DOI: 10.1016/j.rse.2019.111230.

Rutter, N., Sandells, M.S., Derksen, C., King, J., Toose, P., Wake, L., Watts, T., Essery, R., Roy, A.R., Royer, A., Marsh, P., Larsen, C., Sturm, M., 2019. Effect of snow microstructure variability on Ku-band radar snow water equivalent retrievals. The Cryosphere, 13(11): 3045–3059. DOI: 10.5194/tc-13-3045-2019.

Dolant, C., Langlois, A., Brucker, L., Royer, A., Roy, A.R., Montpetit, B., 2018. Meteorological inventory of rain-on-snow events in the Canadian Arctic Archipelago and satellite detection assessment using passive microwave data. Physical Geography, 39(5): 428-444. DOI: 10.1080/02723646.2017.1400339.

Dolant, C., Montpetit, B., Langlois, A., Brucker, L., Zolina, O., Johnson, C., Royer, A., Smith, P., 2018. Assessment of the Barren Ground caribou die‐off during winter 2015–2016 using passive microwave observations. Geophysical Research Letters, 45(10): 4908-4916. DOI: 10.1029/2017GL076752.

Larue, F., Royer, A., DeSève, D., Roy, A.R., Cosme, E., 2018. Assimilation of passive microwave AMSR-2 satellite observations in a snowpack evolution model over northeastern Canada. Hydrology and Earth System Sciences, 22(11): 5711-5734. DOI: 10.5194/hess-22-5711-2018.

Larue, F., Royer, A., DeSève, D., Roy, A.R., Picard, G., Vionnet, V., Cosme, E., 2018. Simulation and assimilation of passive microwave data using a snowpack model coupled to a calibrated radiative transfer model over North‐Eastern Canada. Water Resources Research, 54(7): 4823-4848. DOI: 10.1029/2017WR022132.

Lyu, H., McColl, K.A., Li, X., Derksen, C., Berg, A., Black, T.A., Euskirchen, E., Loranty, M.M., Pulliainen, J., Rautiainen, K., Rowlandson, T., Roy, A.R., Royer, A., Langlois, A., Stephens, J., Lu, H., Entekhabi, D., 2018. Validation of the SMAP freeze/thaw product using categorical triple collocation. Remote Sensing of Environment, 205: 329-337. DOI: 10.1016/j.rse.2017.12.007.

Marchand, N., Royer, A., Krinner, G., Roy, A.R., Langlois, A., Vargel, C., 2018. Snow-covered soil temperature retrieval in Canadian Arctic permafrost areas, using a land surface scheme informed with satellite remote sensing data. Remote Sensing, 10(11), 1703. DOI: 10.3390/rs10111703.

Mavrovic, A., Roy, A.R., Royer, A., Filali, B., Boone, F., Pappas, C., Sonnentag, O., 2018. Dielectric characterization of vegetation at L band using an open-ended coaxial probe. Geoscientific Instrumentation, Methods and Data Systems, 7(3): 195-208. DOI: 10.5194/gi-7-195-2018.

Montpetit, B., Royer, A., Roy, A.R., Langlois, A., 2018. In-situ passive microwave emission model parameterization of sub-arctic frozen organic soils. Remote Sensing of Environment, 205: 112-118. DOI: 10.1016/j.rse.2017.10.033.

Prince, M., Roy, A.R., Brucker, L., Royer, A., Kim, Y., Zhao, T., 2018. Northern Hemisphere surface freeze–thaw product from Aquarius L-band radiometers. Earth System Science Data, 10(4): 2055-2067. DOI: 10.5194/essd-10-2055-2018.

Roy, A.R., Leduc-Leballeur, M., Picard, G., Royer, A., Toose, P., Dersken, C., Lemmetyinen, J., Berg, A., Rowlandson, T., Schwank, M., 2018. Modelling the L-band snow-covered surface emission in a winter canadian prairie environment. Remote Sensing, 10, 1451. DOI: 10.3390/rs10091451.

Blanchard, Y., Royer, A., O'Neill, N., Turner, D.D., Eloranta, E.W., 2017. Thin ice clouds in the Arctic: cloud optical depth and particle size retrieved from ground-based thermal infrared radiometry. Atmospheric Measurement Techniques, 10: 2129-2147. DOI: 10.5194/amt-10-2129-2017.

Busseau, B.-C., Royer, A., Roy, A.R., Langlois, A., Domine, F., 2017. Analysis of snow-vegetation interactions in the low Arctic-Subarctic transition zone (northeastern Canada). Physical Geography, 38(2): 159-175. DOI: 10.1080/02723646.2017.1283477.

Derksen, C., Xu, X., Dunbar, R.S., Colliander, A., Kim, Y., Kimball, J.S., Black, T.A., Euskirchen, E., Langlois, A., Loranty, M.M., Marsh, P., Rautiainen, K., Roy, A.R., Royer, A., Stephens, J., 2017. Retrieving landscape freeze/thaw state from Soil Moisture Active Passive (SMAP) radar and radiometer measurements. Remote Sensing of Environment, 194: 48-62. DOI: 10.1016/j.rse.2017.03.007.

Langlois, A., Johnson, C.-A., Montpetit, B., Royer, A., Blukacz-Richards, E.A., Neave, E., Dolant, C., Roy, A.R., Arhonditsis, G., Kim, D.-K., Kaluskar, S., Brucker, L., 2017. Detection of rain-on-snow (ROS) events and ice layer formation using passive microwave radiometry: A context for Peary caribou habitat in the Canadian Arctic. Remote Sensing of Environment, 189: 84-95. DOI: 10.1016/j.rse.2016.11.006.

Larue, F., Royer, A., DeSève, D., Langlois, A., Roy, A.R., Brucker, L., 2017. Validation of GlobSnow-2 snow water equivalent over Eastern Canada. Remote Sensing of Environment, 194: 264-277. DOI: 10.1016/j.rse.2017.03.027.

Ouellet, F., Langlois, A., Blukacz-Richards, E.A., Johnson, C., Royer, A., Neave, E., Larter, N.C., 2017. Spatialization of the SNOWPACK snow model for the Canadian Arctic to assess Peary caribou winter grazing conditions. Physical Geography, 38(2): 143-158. DOI: 10.1080/02723646.2016.1274200.

Roy, A.R., Toose, P., Derksen, C., Rowlandson, T., Berg, A.A., Lemmetyinen, J., Royer, A., Tetlock, E., Helgason, W., Sonnentag, O., 2017. Spatial variability of L-band brightness temperature during freeze/thaw events over a prairie environment. Remote Sensing, 9(9): 894. DOI: 10.3390/rs9090894.

Roy, A.R., Toose, P., Williamson, M., Rowlandson, T., Derksen, C., Royer, A., Berg, A.A., Lemmetyinen, J., Arnold, L., 2017. Response of L-Band brightness temperatures to freeze/thaw and snow dynamics in a prairie environment from ground-based radiometer measurements. Remote Sensing of Environment, 191: 67-80. DOI: 10.1016/j.rse.2017.01.017.

Royer, A., Roy, A.R., Montpetit, B., Saint-Jean Rondeau, O., Picard, G., Brucker, L., Langlois, A., 2017. Comparison of commonly-used microwave radiative transfer models for snow remote sensing. Remote Sensing of Environment, 190: 247-259. DOI: 10.1016/j.rse.2016.12.020.

Toose, P., Roy, A.R., Solheim, F., Derksen, C., Watts, T., Royer, A., Walker, A., 2017. Radio-frequency interference mitigating hyperspectral L-band radiometer. Geoscientific Instrumentation, Methods and Data Systems, 6(1): 39-51. DOI: 10.5194/gi-6-39-2017.

Wigneron, J.-P., Jackson, T.J., O'Neill, P., De Lannoy, G., de Rosnay, P., Walker, J.P., Ferrazzoli, P., Mironov, V., Bircher, S., Grant, J.P., Kurum, M., Schwank, M., Munoz-Sabater, J., Das, N., Royer, A., Al-Yaari, A., Al Bitar, A., Fernandez-Moran, R., Lawrence, H., Mialon, A., Parrens, M., Richaume, P., Delwart, S., Kerr, Y., 2017. Modelling the passive microwave signature from land surfaces: A review of recent results and application to the L-band SMOS & SMAP soil moisture retrieval algorithms. Remote Sensing of Environment, 192: 238-262. DOI: 10.1016/j.rse.2017.01.024.

Dolant, C., Langlois, A., Montpetit, B., Brucker, L., Roy, A.R., Royer, A., 2016. Development of a rain-on-snow detection algorithm using passive microwave radiometry. Hydrological Processes, 30(18): 3184-3196. DOI: 10.1002/hyp.10828.

Papasodoro, C., Royer, A., Langlois, A., Berthier, É., 2016. Potential of RADARSAT-2 stereo radargrammetry for the generation of glacier DEMs. Journal of Glaciology, 62(233): 486-496. DOI: 10.1017/jog.2016.44.

Roy, A.R., Royer, A., St-Jean-Rondeau, O., Montpetit, B., Picard, G., Mavrovic, A., Marchand, N., Langlois, A., 2016. Microwave snow emission modeling uncertainties in boreal and subarctic environments. The Cryosphere, 10(2): 623-638. DOI: 10.5194/tc-10-623-2016.

André, C., Ottlé, C., Royer, A., Maignan, F., 2015. Land surface temperature retrieval over circumpolar Arctic using SSM/I–SSMIS and MODIS data. Remote Sensing of Environment, 162: 1-10. DOI: 10.1016/j.rse.2015.01.028.

Courtemanche, B., Montpetit, B., Royer, A., Roy, A.R., 2015. Creation of a lambertian microwave surface for retrieving the downwelling contribution in ground-based radiometric measurements. IEEE Transactions on Geoscience and Remote Sensing, 12(3): 462-466. DOI: 10.1109/LGRS.2014.2346138.

Montpetit, B., Royer, A., Wigneron, J.-P., Chanzy, A., Mialon, A., 2015. Evaluation of multi-frequency bare soil microwave reflectivity models. Remote Sensing of Environment, 162: 186-195. DOI: 10.1016/j.rse.2015.02.015.

Papasodoro, C., Berthier, É., Royer, A., Zdanowicz, C., Langlois, A., 2015. Area, elevation and mass changes of the two southernmost ice caps of the Canadian Arctic Archipelago between 1952 and 2014. The Cryosphere, 9: 1535-1550. DOI: 10.5194/tc-9-1535-2015.

Roy, A.R., Royer, A., Derksen, C., Brucker, L., Langlois, A., Mialon, A., Kerr, Y.H., 2015. Evaluation of spaceborne L-band radiometer measurements for terrestrial freeze/thaw retrievals in Canada. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 8(9): 4442-4459. DOI: 10.1109/JSTARS.2015.2476358.

Bergeron, J., Royer, A., Turcotte, R., Roy, A.R., 2014. Snow cover estimation using blended MODIS and AMSR-E data for improved watershed-scale spring streamflow simulation in Quebec, Canada. Hydrological Processes, 28: 4626-4639. DOI: 10.1002/hyp.10123.

Dupont, F., Picard, G., Royer, A., Fily, M., Roy, A.R., Langlois, A., Champollion, N., 2014. Modeling the microwave emission of bubbly ice: Applications to blue ice and superimposed ice in the Antarctic and Arctic. IEEE Transactions on Geoscience and Remote Sensing, 52(10): 6639-6651. DOI: 10.1109/TGRS.2014.2299829.

Langlois, A., Bergeron, J., Brown, R., Royer, A., Harvey, R., Roy, A.R., Wang, L., Thériault, N., 2014. Evaluation of CLASS 2.7 and 3.5 simulations of snow properties from the Canadian Regional Climate Model (CRCM4) over Québec, Canada. Journal of Hydrology, 15(4): 1325-1343. DOI: 10.1175/JHM-D-13-055.1.

Picard, G., Royer, A., Arnaud, L., Fily, M., 2014. Influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around Dome C in Antarctica. The Cryosphere, 8: 1105-1119. DOI: 10.5194/tc-8-1105-2014.

Roy, A.R., Royer, A., Hall, R.J., 2014. Relationship between forest microwave transmissivity and structural parameters for the canadian boreal forest. IEEE Transactions on Geoscience and Remote Sensing, 11(10): 1802-1806. DOI: 10.1109/LGRS.2014.2309941.

Rutter, N., Sandells, M., Derksen, C., Toose, P., Royer, A., Montpetit, B., Langlois, A., Lemmetyinen, J., Pulliainen, J., 2014. Snow stratigraphic heterogeneity within ground-based passive microwave radiometer footprints: Implications for emission modeling. Journal of Geophysical Research, 119(3): 550–565. DOI: 10.1002/2013JF003017.

Chokmani, K., Bernier, M., Royer, A., 2013. A merging algorithm for regional snow mapping over Eastern Canada from AVHRR and SSM/I data. Remote Sensing, 5(11): 5463-5487. DOI: 10.3390/rs5115463.

Montpetit, B., Royer, A., Roy, A.R., Langlois, A., Derksen, C., 2013. Snow microwave emission modeling of ice lenses within a snowpack using the Mircowave Emission Model of Layered Snowpacks (MEMLS). IEEE Transactions on Geoscience and Remote Sensing, 51(9): 4705-4717. DOI: 10.1109/TGRS.2013.2250509.

Picard, G., Brucker, L., Roy, A.R., Dupont, F., Fily, M., Royer, A., Harlow, C., 2013. Simulation of the microwave emission of multi-layered snowpacks using the Dense Media Radiative transfer theory: the DMRT-ML model. Geoscientific Model Development, 6(4): 1061-1078. DOI: 10.5194/gmd-6-1061-2013.

Roy, A.R., Picard, G., Royer, A., Montpetit, B., Dupont, F., Langlois, A., Derksen, C., Champollion, N., 2013. Brightness temperature simulations of the Canadian seasonal snowpack driven by measurements of the snow specific surface area. IEEE Transactions on Geoscience and Remote Sensing, 51(9): 4692-4704. DOI: 10.1109/TGRS.2012.2235842.

Roy, A.R., Royer, A., Montpetit, B., Bartlett, P.A., Langlois, A., 2013. Snow specific surface area simulation using the one-layer snow model in the Canadian LAnd Surface Scheme (CLASS). The Cryosphere, 7: 961-975. DOI: 10.5194/tc-7-961-2013.

Derksen, C., Smith, S.L., Sharp, M., Brown, L., Howell, S., Copland, L., Mueller, D.R., Gauthier, Y., Fletcher, C., Tivy, A., Bernier, M., Bourgeois, J., Brown, R., Burn, C., Duguay, C., Kushner, P., Langlois, A., Lewkowicz, A., Royer, A., Walker, A., 2012. Variability and change in the canadian cryosphere. Climatic Change, 115(1): 59-88. DOI: 10.1007/s10584-012-0470-0.

Dupont, F., Royer, A., Langlois, A., Gressent, A., Picard, G., Fily, M., Cliche, P., Chum, M., 2012. Monitoring the melt season length of the Barnes Ice Cap over the 1979–2010 period using active and passive microwave remote sensing data. Hydrological Processes, 26(17): 2643–2652. DOI: 10.1002/hyp.9382.

Köhn, J., Royer, A., 2012. Microwave brightness temperature as an indicator of near-surface air temperature over snow in Canadian northern regions. International Journal of Remote Sensing, 33(4): 1126-1138. DOI: 10.1080/01431161.2010.550643.

Langlois, A., Royer, A., Derksen, C., Montpetit, B., Dupont, F., Goïta, K., 2012. Coupling the snow thermodynamic model SNOWPACK with the Microwave Emission Model of Layered Snowpacks (MEMLS) for subartic and arctic snow water equivalent retrievals. Water Resources Research, 48(12): W12524. DOI: 10.1029/2012WR012133.

Montpetit, B., Royer, A., Langlois, A., Cliche, P., Roy, A.R., Champollion, N., Picard, G., Domine, F., Obbard, R., 2012. New shortwave infrared albedo measurements for snow specific surface area retrieval. Journal of Glaciology, 58(211): 941-952. DOI: 10.3189/2012JoG11J248.

Roy, A.R., Royer, A., Wigneron, J.-P., Langlois, A., Bergeron, J., Cliche, P., 2012. A simple parameterization for a boreal forest radiative transfer model at microwave frequencies. Remote Sensing of Environment, 124: 371-383. DOI: 10.1016/j.rse.2012.05.020.

Brucker, L., Royer, A., Picard, G., Langlois, A., Fily, M., 2011. Hourly simulations of the microwave brightness temperature of seasonal snow in Quebec, Canada, using a coupled snow evolution-emission model. Remote Sensing of Environment, 115(8): 1966-1977. DOI: 10.1016/j.rse.2011.03.019.

Langlois, A., Royer, A., Dupont, F., Roy, A.R., Goïta, K., Picard, G., 2011. Improved corrections of forest effects on passive microwave satellite remote sensing of snow over boreal and subarctic regions. IEEE Transactions on Geoscience and Remote Sensing, 49(10): 3824-3837. DOI: 10.1109/TGRS.2011.2138145.

Touré, A.M., Goïta, K., Royer, A., Kim, E.J., Durand, M., Margulis, S.A., Lu, H., 2011. A case study of using a multi-layered thermodynamical snow model for radiance assimilation. IEEE Transactions on Geoscience and Remote Sensing, 49(8): 2828-2837. DOI: 10.1109/TGRS.2011.2118761.

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