2013 brought record levels of dust to Colorado’s mountains
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’sCooperative Institute for Research in Environmental Sciences was aimed at updating previous work with data from those heavy dust years.
Dust abatement could be part of a climate adaptation strategy in the Upper Colorado River Basin
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.
Tracking calcium deposits shows big increase in dust deposition in the past couple of decades
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 “Colorado scientists quantify increased dust pollution”→
Asian dust arriving over North America in significant quantities
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 “New dust studies help pinpoint impact on Colorado snow”→
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).
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.