STEVE INSKEEP, host:
The Colorado Rockies have been blasted by six dust storms since last December. That is the worst it's been in at least two decades. And dust does not just make the snow look ugly, it makes the snow melt more quickly. That can spell trouble for farmers, power companies, and others who rely on the water from that melting snow. Scientists recently skied up into the mountains to measure the effect, as NPR's Richard Harris reports.
RICHARD HARRIS reporting:
It's a beautiful day in the Colorado Rockies, as Thomas Painter steers his car over one of the many mountain passes. But the blue sky isn't quite blue enough for Painter's trained eye. He suspects we're driving through the sixth high-altitude dust storm of the year.
Dr. THOMAS H. PAINTER (Research Scientist, National Snow and Ice Data Center, University of Colorado): Now, this will be exciting. This will be the first one that I've seen. I always see the remnants of it, but I never see them happen.
HARRIS: Painter continues to crane his neck as he studies the sky. He says this dust might have blown all the way from China. He's dying to get up to the snow so he can sample it, study it, and worry about it. As we wind into the San Juan Mountains in southwestern Colorado, dust becomes more apparent.
Dr. PAINTER: Wow. This is very pink snow for this early.
(Soundbite of laughter)
HARRIS: Not Cat In The Hat pink, but clearly not white, either, the way the snow usually is in the middle of spring.
Dr. PAINTER: Wow! This is big.
HARRIS: The next day, Tom Painter drives up Red Mountain Pass and straps on mountaineering skis to get a closer look.
(Soundbite of slamming door)
Dr. PAINTER: There you go.
HARRIS: Dust is a big deal. It makes snow darker, and dark snow melts fast -too fast. In fact, it's a much bigger effect than even global warming.
Dr. PAINTER: Understanding when the snow melts, how fast it comes out of the mountains, translates into billions of dollars in agriculture and hydroelectric, recreation.
HARRIS: Reservoirs overflow if they get too much water too early in the season. And then they run low later in the summer. And whitewater guides depend on a flow of water through the summer. And that's in jeopardy if dust makes the snow melt early in one huge rush. Likewise, skiers like Painter find it at the very least, unsettling.
Dr. PAINTER: It's hard to properly wax for dust.
HARRIS: But scientists know surprisingly little about the effect of natural dust balls on snow. Painter says he knows of only one other team anywhere in the world studying it. So he can't reach back to previous research to predict how badly water resources will be thrown off kilter by this year's dust storms. The subject may be neglected in part because of it's usually not obvious that dust is darkening the surface of the snow.
Dr. PAINTER: The first couple of years that we were doing this, I kept taking my sunglasses off, to try to get the sunscreen out of them. And there wasn't any sunscreen in them. And then I'd kick the snow, and it was like ripping down the wall between the black and white and the color part of the Wizard of Oz. All of a sudden, the brilliant white and the little sparkles of blue and red would come back.
HARRIS: Painter says he got captivated by dust after a ski trip with his dad, back when he was in graduate school. One morning, he scrapped dust off a square of snow to expose the brilliant white surface underneath. When they came back at the end of the day, that white patch was no longer a dip, but actually the top of a column standing up from the surface.
Dr. PAINTER: Because it didn't melt away as quickly. And everywhere else was melting away dramatically that day. And so, my father started drilling me with questions about where did the dust come from. How often does the dust come? And why does it accumulate at the surface? And I realized I didn't know any of the answers to these questions. So…
HARRIS: So, thus was born a scientific career.
Dr. PAINTER: And it turns out, it's a much bigger issue than I had even thought.
HARRIS: On this day, nine scientists and technicians are in this wilderness. Most, like Painter, are affiliated with the National Snow and Ice Data Center at the University of Colorado. Collaborator Chris Landry is from the tiny Center for Snow and Avalanche Studies in nearby Silverton. As we come upon him, he's carefully cutting a square out of the snow with an old-fashioned carpenter saw.
Mr. CHRISTOPHER C. LANDRY (Executive Director, Snow and Avalanche Study): What we're doing here, a so-called bulk sample of snow with dust in it. This is the dust that fell last night while you were driving in.
HARRIS: Particles from this square of snow will be tested back in the lab, so Tom Painter can find out where they came from - whether Mongolia, the Mojave Desert, or Monument Valley, Arizona on the Colorado Plateau.
(Soundbite of the cutting of snow squares)
HARRIS: But where it comes from is just part of the puzzle. The more pressing question is what it will do to the snow, how fast it will make it melt. To find out, they've dug a pit through more than eight feet of snow to look at dust layers from the five previous storms.
Mr. LANDRY: Snow water equivalents of the…
HARRIS: Samples tell them the snow is already very close to its melting point. And some layers are already laden with water. That means the snow pack isn't likely to stick around long this season. Ultimately, the scientists want to be able to predict how a given amount of dust will affect the snowmelt, so they can tell water managers down the Colorado and Rio Grande Rivers what to expect in future years.
Unidentified Man: (On radio) (unintelligible)
HARRIS: Painter runs one experiment, but he's also anxious to press on toward the basin's highpoint, a rocky outcropping at 13,500 feet. He promises it will be worth the effort.
Dr. PAINTER: So steady up this hill. And always make sure you have one ski planted.
HARRIS: Finally, we reach the top.
Dr. PAINTER: Pretty amazing, huh?
HARRIS: Far below us, on the other side of the mountain, we can see the town of Telluride. Stretching out into the distance is the Colorado Plateau. That's the source of most of the dust that hits the Rockies. The occasional dust storm from China is a reminder, though, that this is a global problem. Dust blows around the world, and it also falls on snow all around the world.
Dr. PAINTER: The Alps receive dust from the Sahara. And the Taklamakan in western China and the Gobi are depositing dust into the mountain ranges in northwest China and Mongolia.
HARRIS: Arizona, Utah, Mongolia, and the Sahara all generate dust for similar reasons: human activities are disrupting the natural barrier that usually keeps dirt on the ground. And Painter says that's only getting worse.
Dr. PAINTER: And there's strong suggestion that there's going to be an intensification of the use of these semi-arid lands.
HARRIS: Which means more dust.
Dr. PAINTER: Which means more dust. Which means more dust on snow. Which means more absorbed sunlight and more of enhanced snowmelt.
HARRIS: Someday, Painter wants to tackle the global question of dust. But for now, he says, it's exciting to take on the scientific challenge in his own backyard. But it's also worrying. He thinks of his pregnant wife and his future family.
Dr. PAINTER: As a participant in society, it's a bit troubling wondering - with my son coming into the world - am I, in 15 years, going to tell him what snow used to look like?
HARRIS: That depends on how the lands far below this mountain peak are treated by the human beings who stir up the dust in the first place.
Richard Harris, NPR News.
INSKEEP: You can see what a giant dust storm looks like as it sweeps over the sea from China by going to npr.org. And tomorrow, we will go into the desert to see where the dust is coming from.
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INSKEEP: This is NPR News.