The Rear End

The River’s Breath

Here in the dead of winter, why do our rivers smoke?

Mike Paulus, photos by Andrea Paulseth |

If you live here long enough, you’ll see it. The river smoke. In the raw stretches of winter, when the air is thin and the sun is a cold, white fire ... the smoke will rise from the water. It hangs there, brooding along the river’s frigid spine. The Chippewa, the Eau Claire – they are dragons of bitter water, twisting through the city. Their malice blooms in the air. A chill warning. We look away, keep our shoulders all hunched up. We scurry into our warm buildings and our heated cars. We are bugs – escaping.

It can be a scary thing. The smoke (steam? fog? mist?) seems to bloom over the rivers only at winter’s coldest hour, when the subzero weather settles in for days or weeks at a time. It is evil and aggressive. The river is threatening us with its cold.

After years of seeing the smoke – and years of hearing people gasp at the spectacle – I realized I had no idea what caused it. On a day when the air outside is so sharp and dry, how could fat plumes of fog rise from the river? I wanted to know. So I asked around.

And I got a really boring explanation.

First off, if you know anything about me, you know this: When I have question about science, I don’t screw around. And that’s why I recently exchanged some pleasant emails with Dr. Lyle Ford, professor and chair of UW-Eau Claire’s Department of Physics and Astronomy.

The smoke (steam? fog? mist?) seems to bloom over the rivers only at winter’s coldest hour, when the subzero weather settles in for days or weeks at a time. It is evil and aggressive. The river is threatening us with its cold.

I asked Dr. Lyle (as I call him) about the nature of the arctic demon lurking just beneath the surface of our rivers, spewing its ice-breath at passing mortals in a wicked celebration of subzero temperatures. Of the river beast, Dr. Lyle had this to say:

“Let’s see if I can answer your question. The reason the mist forms is that the water is evaporating. When it gets really cold, the water gets cold too, which means it loses energy. That lost energy heats the surface of the water giving some of the water molecules there enough energy to escape the liquid. Of course, the air above is really cold too, so the recently vaporized molecules lose their energy and re-condense with other nearby evaporated water molecules. This forms tiny water droplets just above the surface. These water droplets are exactly the same things that are in clouds, so that’s why we see the mist, fog, or whatever you want to call it. Does that help?”

Yeah, I guess that helps. Kinda. I was hoping to hear about some kind of vile, wintertime black magic, but I guess “exactly the same as clouds” will work. Thanks for the help, Dr. Lyle.

I also contacted LeAnn Lombardo, part of WQOW-News 18’s squad of meteorologists. LeAnnLombo (as I call her) told me this:

“Compare it to when we see our breath on a cold winter day. When you breathe out warm, moist air from your lungs into the cold air, it’s forced to turn into a liquid through condensation. The same goes for the ‘steam’ you see over a river or lake.”

Hmm. While I absolutely appreciate the time it took our local experts to correspond with me on this (which included politely ignoring my use of phrases like “ice voodoo” and “glacier banshees”) I gotta say ... I was disappointed. The river smoke you see in the deathly cold of winter is essentially the same phenomenon you see on a really humid day in August. It’s pretty cool on a molecular level, but we’ve seen it all before.

However. Even if the science behind wintertime river fog is less than titillating, our reaction to it is important. When joined by super low temperatures and a relentless windchill, our mind transforms it into something dangerous. And that’s good. Because of hypothermia.

And hey, if you keep LeAnnLombo’s meteorological comparison in mind – that river smoke is like our very own breath – it’s easy to imagine that our rivers are alive. That they are massive polar worms, lying in silence. Breathing. Waiting for an icy trumpet blast, the signal to rise up and conquer us all.

And sometimes, that’s what I choose to believe.