4 ms·
When the sand falls on the snow in the Alps, it increases the ability of the snow to absorb heat from the sun (because it's darker -- this is known as "albedo")
by tony_cannistra 6y ago
When the sand falls on the snow in the Alps, it increases the ability of the snow to absorb heat from the sun (because it's darker -- this is known as "albedo") which accelerates the melting of the snow. This happens in the Western United States too, and has been studied [0] as a source of uncertainty in predicting snow melt timing (e.g. for things like water availability).
[0]: https://www.pnas.org/content/107/40/17125.short https://www.pnas.org/content/107/40/17125.short
- eCa 6y agoThis effect is also in play in the arctic, but there it is the dark (compared to ice) sea that absorbs more energy.
- Sharlin 6y agoAlso soot that decreases the albedo of snow. On a smaller scale this effect is also readily visible in just about any city that gets snowfall, especially in the spring!
- teeray 6y agoAs a former competitive alpine ski racer, that effect plus the abrasion of the sand itself would make for some very interesting wax choices. “Wetter” usually means a softer wax, but softer waxes don’t stand up to abrasion like that. I’d be interested where the majority of the sand ends up on a mountain and how it gets distributed through the snowpack when groomed out.
- smcl 6y agoFunny, I went through Raytracing In One Weekend[0] recently and encountered the word "albedo" there for the first time in my life. Since then I feel like I've read it or heard it nearly every day! Anyway, thanks for being today's "albedo" guy :-D [0] = https://raytracing.github.io/books/RayTracingInOneWeekend.html https://raytracing.github.io/books/RayTracingInOneWeekend.ht...
- ojilles 6y agoThere’s a phenomenon for that called Baader-Meinhof. https://en.wikipedia.org/wiki/Frequency_illusion https://en.wikipedia.org/wiki/Frequency_illusion