Mongolian Dust Reaches Arizona
April 26 -- Paul Ostapuk thought a band of dark air extending across the western horizon looked a bit odd as his plane descended into Page, Ariz., but he had no way of knowing then just how odd it would turn out to be.
That's one of the few areas left in the country where the air is normally so clear you can see for 100 miles, and there had been no suggestion of an approaching storm in the weather report, so Ostapuk grew increasingly curious about the enormous cloud.
"It was pretty dramatic," says Ostapuk, a meteorologist and air quality specialist with Arizona's Salt River Project, the second largest producer of electricity in the state. The cloud, which he saw for the first time at around 4:30 p.m. on April 12, appeared to undulate, and within a couple of hours had spread across the entire sky.
Traveling Storm
The air was so thick with tiny particulates that it seemed as though the sun was setting prematurely, and astronomers at the Lowell Observatory in nearby Flagstaff would later report seeing rings around the sun, a clear indication that this was no ordinary cloud.
"My first impression was that there had been a volcanic eruption," says Ostapuk, but a quick review of news reports and other resources ruled that out.
And there were no wildfires or other possible sources in the area, so this was clearly a very strange beast.
Ostapuk turned to a NASA Web site with rich data available from a satellite launched less than five years ago. The Total Ozone Mapping Spectrometer (TOMS) provides continuous mapping of ozone and other aerosols, such as sulfur dioxide from volcanic eruptions, around the world.
He then backtracked the cloud, checking where it had been on each previous day.
And finally it hit him. It was clear that the dust he saw descending on Page had come from a massive storm so far away that it seems unthinkable it would have had such a dramatic impact in the small Arizona town.
The storm had occurred in the Gobi Desert of Mongolia and China. That's right folks — the Gobi Desert.
Related Stories
ABC News Live