Slope angle/aspect and sun-cups??

I'm thinking there's maybe an answer to why such a paucity of research on this topic. Who cares? Dirtbag snow-sliders who won't be funding any research grants any time soon...

Jim, I can conceive of a mechanism whereby sun cups and other melt induced irregularities on a glacier surface affect the rate at which it advances and retreats and therefore how it reacts to climate change. In reconstructing paleoclimate and interpreting glacial movements, this would matter.<br><br>I realize you aren't completely serious Corey, but it is worth pointing out that UW has a highly regarded (interdisciplinary) glaciology program and would be a perfect place to study. I work in the Atmospheric Sciences/Geophysics building on campus which houses some (all?) of the glaciologists. Randomly scattered across the walls are large black and white aerial photos (presumably by Austin Post) of huge glaciers. Makes me want to go visit the St. Elias range badly.<br><br>I'm really looking forward to the literature review Amar. I suppose it's pointless to speculate now, but what the heck. I never thought of melt water contributing to sun-cups, but melting snow needs to go somewhere. I'd imagine it moistens the snow locally on the surface and then eventually filters down. Evaporation is proportional to wind speed; with a strong wind on a warm, dry day, a windy slope would evaporate much more of this local melt water (even if it doesn't pool, it could probably be evaporated from the top of the snowpack). Evaporation is a cooling process - it removes the high energy molecules - and would cool the snow surface. The differential heating is radiative and the hot dirt won't be cooled. So cooler snow, still warm dirt -&gt; larger temperature gradient -&gt; more heat transfer and more snow melt, ie, deeper sun cups. If it takes a little while for the water to evaporate and it starts flowing downhill, furrows or runnels could be formed perhaps?<br><br>I think the runnels are caused by melt water channels. I've seen slopes where lots of them converge at a lower flat part just as rivulets of water would.<br><br>The combination of slope angle/aspect matter critically I think. Picture an inclined slope without direct sun, but not shaded. Carve out a sun cup as a step or bench into the slope. The uphill side of the sun cup (the back to the bench) is now completely shaded while the bottom, dirt filled part, is still in the sun. In fact the flat/lower angled part is receiving more sun than the rest of the slope due to the local change in slope angle. Take the same sun cup and put it on a slope with full exposure. The heating is more even, and the flat part is now receiving less sun. Once a sun cup forms, it seems as though it will grow faster on the moderately angled slope without full exposure. That's more than enough pointless speculation from me. Amar clue us in!

Matt, even though I was half-joking (and not sure if I'd have the mindset and time for school again now that I work full-time), what would it take to get into the glaciology program? I have a science background but not much empasis in physics or geology (I studied wildlife science/quantitative methods).<br><br>Yet, opportunities for "research" seem to keep presenting themselves to me.

Matt, even though I was half-joking (and not sure if I'd have the mindset and time for school again now that I work full-time), what would it take to get into the glaciology program? I have a science background but not much empasis in physics or geology (I studied wildlife science/quantitative methods).<br><br>Yet, opportunities for "research" seem to keep presenting themselves to me.

<br><br>I really don't know anything about the glaciology program here, despite the fact that I work in the same building as many of the professors and enjoy their nice photos (I'm a grad student directly tied to the Applied Math department and indirectly to Atmospheric Sciences). From what I gather from their website, it is not its own department, but a group of people working together affiliated with other departments (mostly the Department of Earth and Space Sciences). I imagine you apply to one of these other departments and then somehow specialize in glaciology.<br><br>Here's a link to the Glaciology main page. It has links to the other departments.

For those with a copy of Mountaineering: The Freedom of the Hills or a local library with the same, there is a good discussion of the various forms of snowcover in Appendix One "The Cycle of Snow". <br><br>In the 5th edition, the suncup discussion begins on Page 427 and appears credible including a theory regarding the migration of suncups on a slope.<br><br>The same page also addresses "drainage patterns" a.k.a. "runnels". Enjoy!<br><br>J.P.

however, not all slopes develop the cups, because the3 slope must be gentle enough to pool the melt water from the snow.  on steeper slopes, the same action will lead to rill formation.<br><br>i bet that your experiment would determine that suncups tend to form on lower angle slopes (say, approaching 15deg and less)

<br><br>I was on the nw-facing Vesper glacier last saturday - it was fairly heavily sun-cupped, even at the top, where it is steeper than 40 degrees. There were no runnels.<br><br>The gentle east slopes of the peak were heavily runneled though.<br><br>The mystery deepens.