"These particles, or aerosols, absorb sunlight as it passes through the air, which in combination with the absorption of light by the ozone layer, gives sunrises and sunsets a purple tint," says the release.
In a normal, non-volcanic sunset, light from the sun must travel through a significant amount of the Earth's atmosphere, and blue light is spreading over the aerosols it encounters. This means that less blue light reaches our eyes from directions closer to the sun, causing the sky to appear orange and red.
When volcanic aerosols are present in the stratosphere, the blue light scattered from aerosols near the surface of the Earth may scatter again, this time towards our eyes and cameras. This blue light blends with the red light coming from the sun, giving the sky a purple color.
Lars Kalnajs, an associate in the school's Laboratory for Atmospheric and Space Physics, led the project and said it would explode. is no cause for concern, but warns that we need to prepare for something bigger.
"A really big explosion will have a huge impact on humanity," Kalnajs said in a news release.
"There are crop failures all over the world, and there is ice in the Pennsylvania rivers that did not melt until June." Said Kalnajs.
That's one reason his team is conducting research after the Raikoke explosion. Preliminary data collected to date show that some layers of aerosol in the stratosphere are 20 times thicker than normal in the explosion, according to the news.
"It lets you know that you don't have to put a whole lot of aerosols in order to change its composition," Kalnajs says. "It is a relatively small volcanic eruption, but it is sufficient to affect most of the northern hemisphere."
The group's research is expected to be published later this year.