Heidi of the North! (akutaq) wrote in wtf_nature,
Heidi of the North!

Strange Haze

I live in Alaska. So a couple days ago I noticed a strange haze on the horizon. I just figured the state had another forest fire somewhere and didn't give it a 2nd thought. But, as the days passed I realized there had been no reports of a fire. So why was there a haze?

Because there is a HUGE sandstorm in Mongolia and a HUGE forest fire in Siberia. The wind is just perfect enough that Alaska is getting covered in a haze.

The world doesn't seem so big sometimes.


The cloudy, off-white haze crept into Anchorage over the weekend, obscuring the once-crisp view of the Chugach Mountains with a smog-like quality more akin to a view of the Los Angeles skyline.

But that gunk in our air isn't from car exhausts. Instead, smoke from Russian wildfires and dust kicked up during sandstorms in Mongolia's Gobi Desert are to blame, according to state and federal atmospheric officials.

"It's one of the biggest clouds of dust I've seen on the satellite images in a while," said Gerry Guay, manager of the state's Air Monitoring and Quality Assurance Program. "It covered a fairly extensive area."

Satellite images of the whitish-yellow haze show it stretching hundreds of miles in a solid band east from China and Russia, across Japan and north to the southern tip of Russia's Kamchatka Peninsula.

Alaskans have reported the haze to the National Weather Service, wondering about the cause of the murky skies now spanning the state from Fairbanks to Kodiak and Valdez to the Aleutian Islands, said Sam Albanese, warning coordination meteorologist with the service.

"Initially, I didn't know where it was coming from," Albanese said. "Pretty much (Tuesday) is when we started nailing down what was causing this."

Local dust kicked up by vehicles or construction can contribute to low-altitude air problems, but it generally doesn't rise enough to obscure mountains, Guay said. For that to happen, high winds are needed to fling dust into the air, he said.

Annual sand storms in the Gobi Desert often assault neighboring areas with drifting grit dubbed Kosa, meaning "yellow sand," by the Japanese, whose islands it frequently crosses, said Catherine Cahill, a researcher with the Alaska Volcano Observatory.

Such storms are common through April and May, and the dust routinely reaches Alaska and beyond, she said.

"This is actually fairly normal," she said. "Pretty much every spring, we get a huge amount of dust from the Gobi Desert. Some years we get more dust than others. This is definitely a worse year."

But not the worst in recent years. The spring of 2001 was the fourth-dustiest on record in Asia, with the minuscule dust particles drifting across the entire U.S. and even into Greenland, Cahill said.

This year, dust is only half the problem. Massive wildfires spanning a huge swath of southern Siberia in the Russian Far East broke out last week, contributing smoke to the mix and worsening an unusually dusty spring, Albanese said. One can't smell the smoke because of its lofty position in the sky, he said.

Russian news agency Itar-Tass reported this week that more than 100 forest fires were burning in four Russian regions, including in the Far East and Siberia. Officials declared states of emergency in some districts.

As the dust and smoke drifted across the Alaska Peninsula, Alaska Volcano Observatory ash-detection alarms rang out every few hours as satellites warned of the slowly creeping haze. The equipment mistakenly identified the cloud as a volcanic ash plume, Cahill said.

Researchers who were already collecting atmospheric samples are now planning to test samples of the dust and smoke as well, she said.

"It's nothing to worry about, but it's scientifically interesting," she said.

Anchorage city officials put Tuesday's air quality index at 70, well within the moderate range of between 50 and 100. Indexes above 100 are unhealthy for sensitive groups, while numbers greater than 150 are unhealthy for the public at large, according to the Environmental Protection Agency.

"We've been checking it throughout the day," said Anne Schlapia, air quality specialist with the municipality. "We are keeping an eye on it."

Such a haze typically dissipates in a few days, Guay said, but this one seems to be a bit more stubborn. It will likely linger until later in the week, when a storm system appears poised to move into the region, Albanese said.

"Right now, we're looking at a system moving though Southcentral Thursday or Friday, and if that happens, it will likely clear it out," he said.
Tags: weather
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