A review of the friction of snow skis.

Snow friction results from a mixture of processes. With little meltwater present, the surfaces are partially separated and, when too much water is present, the contact area increases and there may be capillary attachments. Slider thermal conductivity and even colour are very important. Heat is generated by friction and solar radiation absorbtion and is conducted away by both slider and ice particles. The remaining heat is available to generate meltwater which acts as a lubricant. While sliders must be designed for use over a narrow range of snow and weather conditions, polyethylene bases can be structured and waxed to broaden that range. The important processes operate not at the air temperature, but at the ski base temperature, which is highly dependent on such things as snow-surface temperature, load and speed. The roughness elements and contact areas must be characterized before the basic processes can be understood further.