The understanding of the dynamics of the climatic variables is critical to model and predict climatic and environmental changes. Traditional measures collected by the meteorological stations network are dispersedly located throughout the territory in the northern high latitudes and errors associated to these variations can be considerable. Our goal is to evaluate the contribution of the remote sensing by passive microwaves compared to the ground measurements for better characterizing the variations in the surface temperature during the winter. In the presence of snow, extraction of the surface parameters by microwave measurements is a complex and ill-conditioned problem. We evaluated a semi-empirical relation based on a theoretical analysis to estimate the surface temperatures with the measured brightness temperatures at 19 and 37 GHz (vertical polarization). Simulations of emissivity made with the Helsinki Technology University (HUT) model, the knowledge of the land cover, and the forest biomass enable us to define this relationship.The results of the comparison between the calculated surface temperatures and the air temperatures for the entire Canada (137 stations) and for two winters, 1992-93 and 2002-03 (16359 measurements) show a significant correlation with an estimation error ranging between 4 and 7[degrees Celsius] according to the regions considered. These results are discussed according to region and type of land cover (grassland, forest, tundra).

Title: Ventilation - respiratory changes and diffusion of gases in the simulated snow avalanche. Goals: The aim of this study was to investigate different ventilation-respiratory parameters with breathing into the simulated snow avalanche with and without any air pockets. Method: An intervention randomized double blind crossover study was conducted on 12 male students of Military Department at the Faculty of Physical Education and Sports of Charles University. The study was realized in the Krkonoše Mountains in the period January 14 - 18th, 2013 at an altitude of 762 m above sea level. Each volunteer underwent two phases of the experiment in a random order: 1st phase "AP"- breathing into the snow with a 1 L air pocket, and 2nd phase "NP"- breathing into the snow with no air pocket. Physiological parameters, especially fractions of O2 and CO2 in the airways and work of breathing (WoB) expressed as Pressure- Time Product (PTP) were recorded continuously. Results: The presence of the air pockets and size has an important role in the survival of buried avalanche victims. The finding of this study is that it is possible to breath in the avalanche snow even with no air pocket (0 L), but breathing under this condition is associated with significantly increased work of breathing. The limiting factor in no...

Title: Ventilation - respiratory changes and diffusion of gases in the simulated snow avalanche. Goals: The aim of this study was to investigate different ventilation-respiratory parameters with breathing into the simulated snow avalanche with and without any air pockets. Method: An intervention randomized double blind crossover study was conducted on 12 male students of Military Department at the Faculty of Physical Education and Sports of Charles University. The study was realized in the Krkonoše Mountains in the period January 14 - 18th, 2013 at an altitude of 762 m above sea level. Each volunteer underwent two phases of the experiment in a random order: 1st phase "AP"- breathing into the snow with a 1 L air pocket, and 2nd phase "NP"- breathing into the snow with no air pocket. Physiological parameters, especially fractions of O2 and CO2 in the airways and work of breathing (WoB) expressed as Pressure- Time Product (PTP) were recorded continuously. Results: The presence of the air pockets and size has an important role in the survival of buried avalanche victims. The finding of this study is that it is possible to breath in the avalanche snow even with no air pocket (0 L), but breathing under this condition is associated with significantly increased work of breathing. The limiting factor in no...