2500, boul. de l'Université
Université de Sherbrooke
819.821.8000 extension 62506
The objective of this project is to improve the modelling of the passive microwave emission of snow with the DMRT-ML radiative transfer model. This model incorporates various measured properties of the snowpack layers, soil and vegetation in a physical-based model of dense-media radiative transfer which outputs snowpack brightness temperatures. These outputs are compared to the measurements of passive radiometers at five frequencies (1.4, 10.7, 19, 37 and 89 GHz).
An experimental protocol will be developed to isolate homogenous layers of snow in a box transparent to microwaves, and to measure radiometric data at both H and V polarization, successively on an absorbing and reflective background. The inversion of these measurements using a radiative model will allow to calculate absorption and diffusion coefficients, which are data that have never been established for arctic and subarctic snow. Furthermore, the values of these coefficients have never been compared to the values calculated in the DMRT-ML. The characterization of snow will be realized by measuring the density, temperature, specific surface and thermal conductivity using the SnowMicroPen. Tomographic data will also be determined in order to precisely measure the 3D structure of snow grains. Field measurements at different sites (Umiujaq (Nunavik), Forêt Montmorency and Sherbrooke (Québec)) will allow comparison of these parameters for different environments (arctic tundra, boreal forest and mixed forest).
A good characterization of snow and field measurements of absorption and diffusion coefficients of different snow layers will allow to shed new light on the relation between microstructure and microwave interaction with snow.
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.