How a volcanic eruption in Russia caused a purple sunrise in Colorado

BOULDER, Colorado – If you've noticed a purple sunrise in Colorado in recent weeks, know that the reason could be a few thousand miles away.

CU Boulder researchers have collected evidence that suggests a volcanic explosion in Russia as the reason for the colorful sunrises, here in Colorado and elsewhere,

the university said on Thursday

.

Raikoke, located on the Kuril Islands, off the east coast of Russia, erupted in June, sending a thick plume of ash and volcanic gas into the atmosphere and the circulation of a storm on the North Pacific.

NASA satellites observed the eruption and captured impressive images of the plume of smoke.

What the volcano released – CU Boulder researchers learned from a high-altitude balloon – were tiny particles called aerosols, which scatter sunlight as they pass through the air, according to the report. university.

Combined with the absorbent light of the ozone layer, aerosols can produce a shade of purple during sunrises and sunsets. CU Boulder threw the ball near Laramie, Wyo., Last month, after NASA hinted that the eruption had injected sulfur dioxide, likely to form aerosols, announced the university .

"It was a relatively small volcanic eruption, but sufficient to touch most of the northern hemisphere," said Lars Kalnajs, who led the balloon team, in a Press release.

CU Boulder released Thursday the photo of a purple sunrise, taken by

photographer Glenn Randall

. Randall captured the sunrise last month last month as he headed for a stream near Lake Isabella in the wild Indian Peaks.

Kalnajs said the phenomenon – and the aerosols that caused it – should not be worrying.

You will not see the purple sky every morning or night, or anywhere. It depends on the weather conditions.

But if you see the colorful sunrise or sunset, you have already seen something quite rare. According to CU Boulder, the last similar phenomenon occurred in 1991, when Mount Pinatubo erupted in the Philippines.