Kicking Wax and Taking Frames

Cross-country ski tracks along the shore of a lake.
Cross-country ski tracks along the shore of a lake.

Yesterday, a big snowstorm dumped about 30 cm (12″) of snow on Minneapolis, and high winds blew that snow around. On my way home from lab, the train worked well, but I definitely chose correctly when I decided to walk home from the train (2-3 km) rather than take the bus. The roads were a mess, but walking wasn’t too bad.

When that much snow falls that quickly, skiing can be much better for getting around than driving. After dinner I hopped on the skis to go tour around the neighborhood and enjoy being on snow for the first time this winter. I’d barely skied half a block when a car got stuck turning and I helped get them through the intersection.

Skiing around the lake was wonderful. There’s something magical about the quiet of lots of new-fallen snow, and even though the skiing was slow-going, it was fun. However, with it being dark and my being on skis for the first time this winter, I didn’t bring a camera with me.

This morning I went out again and took the camera, because there was a lot of neat stuff to be seen. After helping two more cars get unstuck, I made it to the lake. There were tracks: skis (see photo above), boots, snowshoes, and dogs, plus tire tracks in the roads. High winds had also led to drifting, so there were eolian features as well: mini-dunes, scoops, and even some parabolic or blowout features.

Park bench with snow scoop.
Park bench with snow scoop.

Scoops form when wind has to travel around an object such as a tree, rock, or the legs of a park bench. Because the wind velocity increases on the leading edge of the feature, snow or sand get removed from in front of the obstruction.

Minneapolis on a sunny, snow-covered day.
Minneapolis on a sunny, snow-covered day.

The lake is a great place to look for eolian features, because its flat surface without plants or other obstructions provides a large windy area. Miniature dunes formed, with steep faces to windward, and shallower slopes on the leeward side. In the photo of the lake above, the wind was traveling left-to-right. It also features a pair of cross-country ski tracks!

Blowout feature on the leeward side of a lake.
Blowout feature on the leeward side of a lake.

One of the neat features was this blowout on the south (leeward) side of the lake. Last night it seemed to be a fairly parabolic feature, but today it was clearly a blowout. The grasses slowed the wind and provided a place for snow to accumulate, while the gap between grass tussocks was a high-wind area. Scouring is evident near the gap, but deposition follows not far downwind, and the parabolic shape of the features is visible.

Blowout feature on the leeward side of a lake.
Blowout feature on the leeward side of a lake.

There were a few birds out and about this morning, too! A white-breasted nuthatch was foraging in a tree above me, and several other nuthatches were fluttering around nearby.

White-breasted nuthatch.
White-breasted nuthatch.

It was a fun expedition out skiing, and I was happy to take some pictures along the way. The snowplows were busy while I was out, and several of the streets had been cleared before I got back home, so there were fewer cars to help out of the deep snow.

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AGU 2017, Day 5

Unlike some other years, this year I had a packed day of conferring on the last day. I started out in the posters, because one of the Heard Island presentations was there. On my way to the poster I came across one of the geology professors from my college, and I talked with him a bit about my research. It’s possible I will end up on their seminar schedule. Upon arriving at the poster I was looking for, I learned about the helium isotope composition of bubbles near Heard Island and the McDonald Islands: they’re relatively mantle-like by McDonald, and likely more methane-seeps by Heard.

From there it was on to the exhibit hall, to see a few friends from grad school and make sure I hadn’t missed anything too exciting at the booths. I checked out a few of the aeronomy posters (about Earth’s ionosphere) to see if I could find any good ideas for speakers at the amateur radio clubs I am now in leadership positions in.

Having had enough of the posters, I decided to go to the session on indigenous knowledge and climate change. It was a particularly interesting session, and I wish more of the conference attendees had been there.

Finally, it was time for lunch with a friend from grad school, then off to the airport to head home.