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Environment: ‘Extreme’ dust-on-snow events can speed runoff in Colorado River Basin by six weeks

2013 brought record levels of dust to Colorado’s mountains

More frequent desert dust storms dropping pollution on the Rocky Mountain snowpack is one of the climate change impacts affect the high country.

More frequent desert dust storms dropping pollution on the Rocky Mountain snowpack is one of the climate change impacts affecting the Colorado high country.

By Bob Berwyn

FRISCO — Dust storms that darken the Rocky Mountain snowpack and speed snowmelt are becoming more extreme, according to new research. Particularly heavy dust-on-snow events can speed the melt-out of the snowpack by a full six weeks, all other factors being equal, said Jeffrey Deems, a researcher with the Western Water Assessment and the National Snow and Ice Data Center.

“In 2006 we were impressed at how much dust there was. Then 2009 turned up, and 2010, and 2013 was the dustiest year we’ve recorded in the San Juans,” Deems said, explaining that the latest study, put together by researchers with NOAA’s Cooperative Institute for Research in Environmental Sciences was aimed at updating previous work with data from those heavy dust years.

Last spring, on April 8, a single 16-hour dust storm dropped more dust on the San Juans than the annual totals in any previous winter since scientists started taking detailed measurements, said Chris Landry, director of the Center for Snow and Avalanche Studies in Silverton, which tracks the dust-on-snow events via a network of observation sites. Continue reading

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Colorado: ‘Extreme’ dust events can speed runoff by 6 weeks

Dust abatement could be part of a climate adaptation strategy in the Upper Colorado River Basin

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Desert dust from the Southwest tints the spring snow cover at Loveland Pass, Colorado.

By Summit Voice

SUMMIT COUNTY — Even before a series of intense dust storms coated the Rocky Mountain snowpack in 2009 and 2010, scientists had calculated that the dust speeds the spring meltdown and reduces runoff in the Colorado River Basin by as much as 5 percent, based on data gathered between 2005 and 2008.

Dust storms in subsequent years saw unprecedented levels of dust loading, on the order of five times the 2005–2008 loading, a team of researchers wrote recently in a paper published for online discussion in the journal Hydrology and Earth System Sciences. Continue reading

Colorado scientists quantify increased dust pollution

Tracking calcium deposits shows big increase in dust deposition in the past couple of decades

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Desert dust taints the snow at Loveland Pass, Colorado, speeding snowmelt and sometimes contributing to avalanche hazards. Bob Berwyn photo.

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NASA satellite images can help track dust storms.

By Bob Berwyn

FRISCO — Significant dust storms the past few years have had a big impact on the timing of snowmelt in the Colorado Rockies, but scientists haven’t been able to say for certain if those events are becoming more frequent.

Now, a new study from the University of Colorado Boulder shows that the amount of dust deposition has increased, at least during the 17-year span covered by the researchers, who tracked calcium deposits to reach their conclusions. Calcium dissolved in precipitation has long been measured by the National Atmospheric Deposition Program as a way assess acid rain.

The scientists reviewed calcium deposition data from 175 NADP sites across the United States between 1994 and 2010, measuring increases in calcium deposition increased at 116 locations. The sites with the greatest increases were clustered in the Northwest, the Midwest and the Intermountain West, with Colorado, Wyoming and Utah seeing especially large increases. Continue reading

New dust studies help pinpoint impact on Colorado snow

Asian dust arriving over North America in significant quantities

Dust from Asia is a big factor in the atmosphere over North America. Map courtesy NASA.

By Summit Voice

SUMMIT COUNTY — The desert Southwest isn’t the only source of dust in the atmosphere over Colorado. As much as 64 million tons of dust from minerals, soils, pollutants and other sources cross the ocean from Asia, carried by prevailing west winds, and mix into over North America each year, according to a NASA study published last spring.

That’s just about about equal to the 69 million tons of aerosols produced domestically by natural processes, transportation, and industrial sources. The tiny particles can affect the climate, as well human health if they mix down into the lower atmosphere.

Dust movement is particularly active in spring, when the rise of cyclones and strong mid-latitude westerlies boost particle transport across the Pacific. In addition to the transport from Asia, North America also imports aerosols from Africa and the Middle East.

“This is a crucial step toward better understanding how these tiny but abundant materials move around the planet and impact climate change and air quality,” said Hongbin Yu, lead author and an atmospheric scientist at the University of Maryland and NASA’s Goddard Space Flight Center. Observing aerosols and quantifying their impact on warming or cooling the planet remains one of the most difficult challenges in climate science. Continue reading

Colorado: Dust layers a factor in record-early snow melt

Report links wind-blown dust with early runoff

Dust from the desert Southwest is visible on the snow at Loveland Pass, Colorado in this file image from 2010.

NASA Satellite images can trace the dust plumes back to their source.

By Summit Voice

SUMMIT COUNTY — Along with above-average temperatures and dry and sunny weather, spring dust storms in March and April likely were a significant factor in this year’s record early snow-melt season, according to the Silverton-based Colorado Center for Snow and Avalanche Studies.

Snow that’s darkened by wind-deposited dust absorbs much more heat and hastens the warming of the snowpack to an isothermal state (32 degrees from top to bottom).

In its year-end report, the center explains that the dust layers continue to absorb and add solar energy to the snowpack long after the original dust layer is deposited.  Continue reading

Colorado: Dust-on-snow research faces funding crunch

San Juan-based research yielding valuable data on snowmelt and runoff

A thick layer of dust is visible on the snow at Loveland Pass, Colorado.

By Bob Berwyn

SUMMIT COUNTY — A critical research program that helps assess the effects of wind-born dust on Colorado’s snowpack and runoff is fighting for financial survival.

To continue operating the Senator Beck Basin long-term monitoring program after this season, the Silverton-based Center for Snow and Avalanche Studies needs to raise a total of $135,000. Private donors have stepped up to the plate with $15,000 so far, while Denver Water has chipped in with $5,000, but the research organization is still a long way from its goal, facing a June 30 funding deadline. Continue reading

Weather: Storm delivers … dust

Coming week looks dry and warm

Most of the moisture in the jet stream is diving south of Colorado.

SUMMIT COUNTY — The latest storm to roll through the Rockies delivered plenty of snow to the San Juans — as promised — but didn’t do a whole lot to boost the dwindling snowpack in the central and northern mountains, where only a few inches were reported.

After cool temps Monday and Tuesday, highs could climb back into the upper 50s by mid week at valley elevations in the high country, with above-normal readings likely through next weekend. Spring has sprung.

Both Telluride and Wolf Creek did well with the southerly flow, picking up about a foot of snow, while Silverton reported 14 inches. Crested Butte and Vail reported 5 inches, with three inches around Aspen.

Perhaps more significantly, the storm brought another significant deposition of desert dust to at least some parts of the high country. According to early reports, dust was reported in the Summit County zone by backcountry observers, said Colorado Avalanche Information Center forecaster Scott Toepfer. Continue reading

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