Showcase April - Phase Changes Of Water On The Lake

I'll repost an old photography post of mine that I think is worth reposting. I took the photos and made the post at the harbor in Lahti on January 18 2019. The morning was very cold but the skies were clear. When the sun rose, interesting things happened over the lake within minutes. Let's take a look.

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Right after sunrise, a thick fog appeared above the snowy frozen over surface of Lake Vesijärvi. Before sunrise, the air was completely clear. In minutes, the fog appeared and started to thicken. Here's what I'm talking about:

ƒ/5.6 270.0 mm 1/800 800

A part of the bay to the north of the boat harbour is between the breakwater in the foreground and the buildings. Why does this happen? Even relatively weak sunshine is enough to cause some of the snow on the lake ice to sublimate directly into water vapor. But because the air was very cold, about - 11 C, the sublimated water vapor immediately condensed into microscopic droplets that made up the fog.

The lake was completely covered by the fog. I had to stop shooting and go to work. But I suspect it didn't take long for the fog to disappear in the sun. The public has been warned against walking on the ice because there is a lot of snow which has insulated the ice from the cold air. The ice will thicken but more slowly than usual. I'm mentioning this because I would've wanted to walk on the ice to be able to make better use of the fog to take photos.

ƒ/5.6 300.0 mm 1/640 800

A couple of pics taken a bit earlier:

ƒ/5.6 55.0 mm 1/50 400

ƒ/5.6 55.0 mm 1/20 1600