Technical snow

The technical snow module contains everything that is required to simulate the technical snow management as performed in ski resorts. This includes both snow grooming and technical snow production. In order to keep the configuration quite simple and to reduce the need for detailed operational data, the grooming operations are simplified: it is assumed that snow grooming is performed between a specific calendar week, everyday at a specific time and ends at another given calendar week. In contrast, there is more flexibility regarding snow production: it is triggered when the forcing data contains positive values in the psum_tech field.

Snow grooming

The densification and mixing of the upper layers of the snow are simulated by the snow grooming module (see TechSnow::preparation). it is configured with the following keys:

• GROOMING_WEEK_START: calendar week when to start grooming operations;
• GROOMING_WEEK_END: calendar week when to end grooming operations;
• GROOMING_HOUR: at what time of the day is snow grooming performed;
• GROOMING_DEPTH_START: minimum snow height necessary for groooming (if there is less than GROOMING_DEPTH_START, grooming will be skipped);
• GROOMING_DEPTH_IMPACT: maximum grooming depth on the snow. Snow layers deeper than GROOMING_DEPTH_IMPACT are left unchanged.

Snow production

When a meteorological forcing named psum_tech has a positive value, snow production will be triggered. The mass of produced snow is given by psum_tech while other properties (such as snow temperature and liquid water content as well as the partition between solid and liquid precipitation) are computed based on the local <a href="https://en.wikipedia.org/wiki/Wet-bulb_temperature"wet bulb temperature. Average values of water losses due to wind and evaporation are assumed together with an average wind speed suitable for snow production (this means that the true, local wind speed is not used, instead it is assumed that the snow production has been triggered because the wind speed was not too high).

More details are given in TechSnow::productionPpt.