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. (more…)

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.  (more…)

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. (more…)

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. (more…)

Weather: Something brewing?

A digging Pacific trough will favor the San Juans for snowfall.

Dust, fire weather, wind — and maybe a bit of snow for the northern mountains

By Bob Berwyn

SUMMIT COUNTY — After more than a week of unseasonably warm and dry weather, winter will make somewhat of a comeback in Colorado, as a southward-digging Pacific storm makes its way inland during the second half of the weekend and early next week.

As of Sunday morning, winter storm warnings were up for some southeastern Utah mountains, as well as watches for parts of the West Elks and the Telluride area.

Much of the rest of the West Slope, along with the Eastern Plains, are under a red flag warning, with high winds, warm temps and low humidity combining for dangerous fire conditions. The warning includes the lower elevations of Eagle County. (more…)

Mountain news roundup

Dust on snow, roadless rule updates, grizzly cubs delight Grand Teton crowds

A slide reveals a dust-on-snow layer underneath in 2010 — photo by Jenney Coberly

Compiled by Jenney Coberly

Dust on snow density less this year than in 2009 and 2010

Snow watchers have counted nine significant dust events in Colorado, but unlike in recent years, the density of the dust seems less this season, especially in the northern and central regions of the state. “We don’t have as much dust on snow layers to enhance the heat that is sure to come … so it removes one variable on how this runoff will come,” said Jim Pokrandt, spokesman for the Colorado River Water Conservation District.

Portions of Colorado’s high country could possibly see snowpack carrying through summer, a rarity in the last decade.

“It is certainly cleaner than it was in the last couple of years, but it still remains to be seen what’s going to happen,” UCLA research scientist Tom Painter said. “It’s certainly an interesting year.”

Read the full article in the Denver Post.

(more…)

Dust-storm season begins in high country

A snow pit clearly shows a recent layer of dust that acummulated during a March 23 wind storm. PHOTO COURTESY COLORADO AVALANCHE INFORMATION CENTER.

Desert dust from Southwest contaminates the Colorado mountain snowpack

By Bob Berwyn

SUMMIT COUNTY — The Colorado high country has experienced its first significant dust event of the season, as southwest winds in March 23 coated the mountain snowpack with a distinct layer of desert dirt.

The dust was most apparent in the southwestern part of the state, but spread as far north as Winter Park and even the Steamboat area, said Brian McCall, a forecaster with the Colorado Avalanche Information Center. The dust layer was clearly visible in snow pits around the region. McCall said the dust doesn’t present an immediate avalanche concern, but bears watching as new snow layers pile up. (more…)

Dust storms implicated in Colorado avalanches

‘… A massive shift in the amount of energy being absorbed by the snow’

 

Pockets of dust and wind-pitted snow are evident in this spring scene at Loveland Pass.

 

 

University of Utah Snow Optics Laboratory graduate students, Annie Bryant and McKenzie Skiles, collect dust-in-snow samples at Swamp Angel Study Plot.

 

By Bob Berwyn

SUMMIT COUNTY — Desert dust blowing on to the high peaks of Colorado is affecting stream flows and even changing tundra vegetation — and now it’s been traced as a cause of avalanches in the high country, researcher Chris Landry said Friday, addressing a packed house at the annual Colorado Snow and Avalanche Workshop.

Scientists have measured a significant increase in the number of dust-on-snow episodes in recent years. They’ve tracked the dust to it sources  in the Southwest, where dry weather and disturbance to desert soils, including off-road use, agriculture and energy development have all been tabbed as contributing factors. (more…)

Dust on snow cuts Colorado River flows by 5 percent

An April storm in Summit Couny delivered a visible layer of red desert dust along with a few inches of wet snow. PHOTO BY BOB BERWYN.

Ground-breaking study quantifies impacts of human land-use patterns in southwestern deserts

By Summit Voice

SUMMIT COUNTY — Desert dust falling on snow in the high country may be cutting Colorado River flows downstream by as much as 5 percent each year — about twice the amount of water that Las Vegas uses annually.

Reducing dust deposition could help boost the Colorado River’s yield, but that would mean changing land-use patterns and human disturbances in the southwestern desert regions, according to Brad Udall, director of the Western Water Assessment. (more…)

Weatherblog: More wind, dust and falling lodgepoles

Wet snow avalanche on Peak 6 in the Tenmile Range near Breckenridge, Colorado.

Big wet snow avalanches ran on many slopes in the backcountry this weekend including on Peak 6, in the Tenmile Range near Breckenridge. PHOTO BY BOB BERWYN.

Climber injured in wet snow slide on Torreys; windy weather to continue, snow in the Wasatch

By Bob Berwyn

SUMMIT COUNTY — Colorado is stuck between a strong high pressure ridge to the east and a big trough over the West Coast, and the pressure gradient between the two systems will continue to bring windy conditions to the high country.

The winds will shift to a westerly direction Monday, bringing a sharp temperature drop, with highs in the lower 40s and chilly night, dropping into the mid-20s. The average high for May 24 is 59 degrees, with the record high of 75 degrees set in 1975. The record low for the day was 17 degrees, set in 1971.

The gusty winds of the past few days also brought another layer of dust to the snowpack and built up some enormous cornices along ridgelines. Watch Jenney Coberly’s dust on snow video for more information, and be aware that the wind could bring down dead lodgepole pines.

Get more weather and avalanche info after the break … (more…)

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