INDIANAPOLIS — If you glanced up Monday or Tuesday, you may have noticed the sun was a glowing red orb in the sky, far ruddier than usual.
That's thanks to wildfires in northern Montana and southwestern Canada and the winds blowing from the northwest, said Andrew White, a meteorologist with the National Weather Service here.
"Some of the smoke has been drifting in from the northwest, drifting in from the atmosphere," he said.
When particles, such as smoke or dust, fill the atmosphere, the longer wavelengths of light — which look red — scatter more effectively. If the air is cleaner, more air molecules scatter shorter wavelengths or light, or blue light, more effectively. (Think clear blue sky.)
► Wednesday: Oregon wildfire closes I-84, jumps river into Washington
► July 2015: Western wildfires affect national icons
► June 2015: Wildfire smoke drifts into USA, creates red sunrises, sunsets
On Wednesday, the wind is continuing to be from the northwest, and that brings with it some residual smoke, White said.
The forecast calls for the wind not to shift until Thursday, so the sun likely will retain its flushed appearance until then if the clouds clear away, he said.
Follow Shari Rudavsky on Twitter: @srudavsky
