River of Fire Smoke Darkens Sun and Moon

My eyes are burning. The morning Sun, already 40° high, glares a lemony-orange. It’s meteorologically clear, but the sky looks like paste. What’s going on here?

Forest fires! Many in the Midwest, northern mountain states and Canadian provinces have been living under a dome of high altitude smoke the past few days reflected in the ruddy midday Sun and bloody midnight Moon.

On June 29, 2015 NASA’s Terra satellite captured this image of a river of smoke pouring across the Canadian provinces and central U.S. from hundreds of wildfires (seen at upper left) in western Canada. The difference in color between clouds true clouds and smoke is obvious. Credit: NASA image courtesy Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team at NASA GSFC
On June 29, 2015 NASA’s Terra satellite captured this image of a river of smoke pouring across the Canadian provinces and central U.S. from hundreds of wildfires (seen at upper left) in western Canada. The difference in color between clouds true clouds and smoke is obvious. Credit: NASA image courtesy Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team at NASA GSFC

Fires raging in the forests of northern Alberta and Saskatchewan have poured tremendous amounts of smoke into the atmosphere. Favorable winds have channeled the fumes into a brownish river of haze flowing south and east across Canada and into the northern third of the U.S. If an orange Sun glares overheard at midday, you’ve got smoke. Sometimes you can smell it, but often you can’t because it’s at an altitude of 1.2 – 3 miles (2-5 km).

The Moon sits at lower right with the star Vega visible at the top of the frame in this 30-second time exposure made last night (July 2) under the pall of forest fire smoke. Credit: Bob King
The Moon sits at lower right with the star Vega visible at the top of the frame in this 30-second time exposure made last night (July 2) under the pall of forest fire smoke. Credit: Bob King

But the visual effects are dramatic. Last night, the nearly full Moon looked so red and subdued, it could easily have been mistaken for a total lunar eclipse. I’ve never seen a darker, more remote-looking Moon. Yes, remote. Without its customary glare, our satellite looked shrunken as if untethered from Earth and drifting away into the deep.

And nevermind about the stars. Try as I might, I could only make out zero magnitude Vega last night. The camera and a time exposure did a little better but not much.

This image taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the Terra satellite on June 30, 2015.  Residents of the states affected by the smoke will notice much more vivid sunsets during the time the smoke is in the air.  The size of the smoke particles is just right for filtering out other colors meaning that red, pink and orange colors can be seen more vividly in the sky. NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team. Caption: NASA/Goddard, Lynn Jenner
This image was taken by the Terra satellite on June 30, 2015. Residents of the states affected by the smoke will notice much more vivid sunsets during the time the smoke is in the air. The size of the smoke particles is just right for filtering out other colors meaning that red, pink and orange colors can be seen more vividly in the sky. NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team. Caption: NASA/Goddard, Lynn Jenner

These days of deep red suns in the middle of the day fiery moons at night are an occasional occurrence across Canada and the northern half of the U.S. during the summer. Our previous bout with fire haze happened in early June as a result of massive wildfires in the Northwest Territories and northern Alberta. A change in wind direction and thorough atmospheric-cleaning by thunderstorms returned our blue skies days later.

Using a prism, we can take white light and spread it apart into its component colors. Credit: NASA
Using a prism, we can take white light and spread it apart into its component colors. Credit: NASA

While the downsides of fire haze range from poor air quality to starless nights, the upside is a more colorful Sun and Moon.

Back in grade school we all learned that white light is made up of every color of the rainbow. On a sunny day, air molecules, which are exceedingly tiny, scatter away the blue light coming from the Sun and color the sky blue. Around sunset and sunrise, when the Sun’s light passes through the lowest, thickest, haziest part of the atmosphere, greens and yellows are also scattered away, leaving an orange or red Sun.

Fire smoke adds billions of smoke particles to the atmosphere which scatter away purples, blues, greens and yellows to turn an otherwise white Sun into a blood red version smack in the middle of the day.

A ring-billed gull is silhouetted against a yellow sky and orange sun early Monday afternoon. Smoke from forest fires across Canada’s Northwest Territories and northern Alberta drifted over the region and colored the the sun orange long before sunset. Credit: Bob King
A ring-billed gull is silhouetted against a yellow sky and orange Sun  in Duluth, Minn. a few weeks back during the previous series of smoky days.This photo was taken around 3 p.m. local time. Credit: Bob King

Keep an eye on the color of the blue sky and watch for red suns at midday. Forest fires are becoming more common and widespread due to climate change. If you’ve never seen this eerie phenomenon, you may soon. For more satellite images of forest fires, check out NASA’s Fires and Smoke site.

I’ve often wondered what it would look like if Earth orbited a red dwarf star instead of the Sun. These smoky days give us a taste.