Modelling the L-Band Snow-Covered Surface Emission in a Winter Canadian Prairie Environment

• Published in: Remote Sensing
• Main Authors: Roy, Alexandre, Leduc-Leballeur, Marion, Picard, Ghislain, Royer, Alain, Toose, Peter, Derksen, Chris, Lemmetyinen, Juha, Berg, Aaron, Rowlandson, Tracy, Schwank, Mike
• Other Authors: Centre d'Applications et de Recherches en TELédétection Sherbrooke (CARTEL), Département de géomatique appliquée Sherbrooke (UdeS), Université de Sherbrooke (UdeS)-Université de Sherbrooke (UdeS), Departement des sciences de l’environnement Trois-Rivieres, Université du Québec à Trois-Rivières (UQTR), Centre d'Etudes Nordiques (CEN), Université Laval Québec (ULaval), Institute of Applied Physics "Nello Carrara" (IFAC), Consiglio Nazionale delle Ricerche (CNR), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ), Climate Research Division Toronto, Environment and Climate Change Canada, Finnish Meteorological Institute (FMI), University of Guelph, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Gamma Remote Sensing Research and Consulting AG
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: L-band emission; snow; WALOMIS; Frozen soil; ground-based radiometer; [SDE]Environmental Sciences; Antarctic; Antarc*
• Online Access: https://hal.archives-ouvertes.fr/hal-03747871; https://hal.archives-ouvertes.fr/hal-03747871/document; https://hal.archives-ouvertes.fr/hal-03747871/file/Roy_2018.pdf; https://doi.org/10.3390/rs10091451

International audience Detailed angular ground-based L-band brightness temperature (TB) measurements over snow covered frozen soil in a prairie environment were used to parameterize and evaluate an electromagnetic model, the Wave Approach for LOw-frequency MIcrowave emission in Snow (WALOMIS), for seasonal snow. WALOMIS, initially developed for Antarctic applications, was extended with a soil interface model. A Gaussian noise on snow layer thickness was implemented to account for natural variability and thus improve the TB simulations compared to observations. The model performance was compared with two radiative transfer models, the Dense Media Radiative Transfer-Multi Layer incoherent model (DMRT-ML) and a version of the Microwave Emission Model for Layered Snowpacks (MEMLS) adapted specifically for use at L-band in the original one-layer configuration (LS-MEMLS-1L). Angular radiometer measurements (30°, 40°, 50°, and 60°) were acquired at six snow pits. The root-mean-square error (RMSE) between simulated and measured TB at vertical and horizontal polarizations were similar for the three models, with overall RMSE between 7.2 and 10.5 K. However, WALOMIS and DMRT-ML were able to better reproduce the observed TB at higher incidence angles (50° and 60°) and at horizontal polarization. The similar results obtained between WALOMIS and DMRT-ML suggests that the interference phenomena are weak in the case of shallow seasonal snow despite the presence of visible layers with thicknesses smaller than the wavelength, and the radiative transfer model can thus be used to compute L-band brightness temperature.