PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

NASA study shows desert dust cuts Colorado River flow

2010-09-22
(Press-News.org) Snowmelt in the Colorado River basin is occurring earlier, reducing runoff and the amount of crucial water available downstream. A new study shows this is due to increased dust caused by human activities in the region during the past 150 years.

The study, led by a NASA scientist and funded by the agency and the National Science Foundation, showed peak spring runoff now comes three weeks earlier than before the region was settled and soils were disturbed. Annual runoff is lower by more than five percent on average compared to pre-settlement levels.

The findings have major implications for the 27 million people in the seven U.S. states and Mexico who rely on the Colorado River for drinking, agricultural and industrial water. The results were published in this week's Proceedings of the National Academy of Sciences.

The research team was led by Tom Painter, a snow hydrologist at both NASA's Jet Propulsion Laboratory in Pasadena, Calif., and UCLA. The team examined the impact of human-produced dust deposits on mountain snowpacks over the Upper Colorado River basin between 1915 and 2003. Studies of lake sediment cores showed the amount of dust falling in the Rocky Mountains increased by 500 to 600 percent since the mid-to-late 1800s, when grazing and agriculture began to disturb fragile but stable desert soils.

The team used an advanced hydrology model to simulate the balance of water flowing into and out of the river basin under current dusty conditions, and those that existed before soil was disturbed. Hydrologic data gathered from field studies funded by NASA and the National Science Foundation, and measurements of the absorption of sunlight by dust in snow, were combined with the modeling.

More than 80 percent of sunlight falling on fresh snow is typically reflected back into space. In the semi-arid regions of the Colorado Plateau and Great Basin, winds blow desert dust east, triggering dust-on-snow events. When dark dust particles fall on snow, they reduce its ability to reflect sunlight. The snow also absorbs more of the sun's energy. This darker snow cover melts earlier, with some water evaporating into the atmosphere.

Earlier melt seasons expose vegetation sooner, and plants lose water to the atmosphere through the exhalation of vapor. The study shows an annual average of approximately 35-billion cubic feet of water is lost from this exhalation and the overall evaporation that would otherwise feed the Colorado River. This is enough water to supply Los Angeles for 18 months.

"The compressed mountain runoff period makes water management more difficult than a slower runoff," Painter said. "With the more rapid runoff under dust-accelerated melt, costly errors are more likely to be made when water is released from and captured in Colorado River reservoirs."

Prior to the study, scientists and water managers had a poor understanding of dust-on-snow events. Scientists knew from theory and modeling studies that dust could be changing the way snowfields reflect and absorb sunlight, but no one had measured its full impact on snowmelt rates and runoff over the river basin. The team addressed these uncertainties by making systematic measurements of the sources, frequency and snowmelt impact of dust-on-snow events.

"These researchers brought together their collective expertise to provide a historical context for how the Colorado River and its runoff respond to dust deposition on snow," said Anjuli Bamzai, program director in the National Science Foundation's Division of Atmospheric and Geospace Sciences in Arlington, Va. "The work lays the foundation for future sound water resource management."

Painter believes steps can be taken to reduce the severity of dust-on-snow events in the Colorado River basin. He points to the impact of the Taylor Grazing Act of 1934 for potential guidance on how dust loads can be reduced. The act regulated grazing on public lands to improve rangeland conditions. Lake sediment studies show it decreased the amount of dust falling in the Rocky Mountains by about one quarter.

"Restoration of desert soils could increase the duration of snow cover, simplifying water management, increasing water supplies and reducing the need for additional reservoir storage of water. Peak runoff under cleaner conditions would then come later in summer, when agricultural and other water demands are greater," Painter said.

"It could also at least partially mitigate the expected regional impacts of climate change, which include reduced Colorado River flows, increased year-to-year variability in its flow rate, and more severe and longer droughts," he added. "Climate models project a seven to 20 percent reduction in Colorado River basin runoff in this century due to climate change."

INFORMATION:

Other institutions participating in the study include the National Snow and Ice Center in Boulder, Colo.; U.S. Geological Survey Southwest Biological Center in Moab, Utah; University of Washington in Seattle; Center for Snow and Avalanche Studies in Silverton, Colo.; and the University of Colorado-NOAA Western Water Assessment in Boulder.

http://www.jpl.nasa.gov/news/news.cfm?release=2010-306

Written by: Alan Buis
NASA's Jet Propulsion Laboratory

END



ELSE PRESS RELEASES FROM THIS DATE:

Farm, forest lands being protected -- but not always for farming or forestry

2010-09-22
CORVALLIS, Ore. – More than 35 years after Oregon began one of the nation's most ambitious land use planning programs, a new study suggests it's still difficult to demonstrate that it has accomplished one of its primary goals – protecting agricultural lands and a thriving forest, farm and ranching industry. There's some evidence that the laws have provided a "measurable degree of protection," scientists say in the report. However, there are also impacts that were little anticipated or considered four decades ago, such as the growth of "hobby farms" in which farming or ...

NASA-funded study shows desert dust cuts Colorado River flow

2010-09-22
Snowmelt in the Colorado River basin is occurring earlier, reducing runoff and the amount of crucial water available downstream. A new study shows this is due to increased dust caused by human activities in the region during the past 150 years. The study, led by a NASA and UCLA scientist and funded by NASA and the National Science Foundation (NSF), showed peak spring runoff now comes three weeks earlier than before the region was settled and soils were disturbed. Annual runoff is lower by more than 5 percent on average, compared with pre-settlement levels. The findings ...

Vitamin D protects against obesity-induced endometrial cancer, GUMC researchers say

2010-09-22
Washington, DC – Findings from an animal study suggest that obese women can reduce their increased risk of endometrial disease if they take vitamin D supplements, say researchers at the Georgetown Lombardi Comprehensive Cancer Center. The scientists report in Cancer Prevention Research published online today that 25 percent of obese mice fed a vitamin D supplemented diet developed endometrial cancer, while 67 percent of obese mice not treated with the vitamin developed cancer. They also report that vitamin D offered no protective effects for normal weight mice; whether ...

New fluorescence technique opens window to protein complexes in living cells

2010-09-22
Fluorescent microscopy makes use of molecules, such as green fluorescent protein (GFP), that emit colored light when illuminated with light of a specific wavelength. Molecules like GFP can be used to label proteins of interest and can reveal information about the relationships of molecules within cells. Fluorescence polarization, also known as anisotropy, is specific parameter of fluorescence that can provide additional information about the properties of individual molecules. Fluorescence anisotropy has been used to study isolated molecules. Now, a recent study describes ...

The Achilles' heel of tendons

2010-09-22
Tendons are the body's marionette strings, connecting bones to muscles that raise an eyebrow or propel us into a full run. That is, until an unusually forceful or awkward pull on the strings leaves us with a sprain, strain or tear. Surgeons attempt to repair over 300,000 of these injuries every year, and doctors visits for sore tendons run into the millions. Using a combination of nanoscience and biomedical and civil engineering to explore tendon structure from atoms on up, researchers have unraveled part of the mystery behind why we have problems with our tendons. A ...

Stroke gene discovered

2010-09-22
A Dutch-German medical research team led by Harald Schmidt from Maastricht University, Netherlands, and Christoph Kleinschnitz, University of Würzburg, Germany, has discovered that an enzyme is responsible for the death of nerve cells after a stroke. The enzyme NOX4 produces hydrogen peroxide, a caustic molecule also used in bleaching agents. Inhibition of NOX4 by an experimental new drug in mice with stroke dramatically reduces brain damage and preserves brain functions, even when given hours after the stroke. These findings will be published next week in the online, open ...

CRP genetic variants crucial in interpreting inflammatory disease activity

2010-09-22
CRP is commonly used as a serum marker for inflammation or infection, but the genetic effects of CRP variants on acute-phase serum CRP concentrations in patients with rheumatoid arthritis may be large enough to have a clinically relevant impact on the assessment of inflammatory disease activity, which in turn may influence therapeutic decision making. Furthermore, failure to take into account the potential for genetic effects may result in the inappropriate reassurance or under-treatment of patients simply because they carry low-CRP associated genetic variants. These are ...

Community health workers can effectively manage children with malaria and pneumonia

2010-09-22
Community Health Workers can safely and effectively provide integrated management of pneumonia and malaria to communities by dispensing amoxicillin to children with non-severe pneumonia and artemether-lumefantrine to children with malaria (after using rapid diagnostic tests). Furthermore, these activities result in a significant increase in the proportion of appropriately-timed antibiotic treatment for non-severe pneumonia and in a significant decrease in inappropriate use of antimalarials. These are the results from a study by Kojo Yeboah-Antwi from the Boston School ...

Too many systematic reviews?

2010-09-22
There are now 75 clinical trials and 11 systematic reviews of trials published every day, with no signs this pace is slowing. How will we ever cope?, ask Hilda Bastian, Paul Glasziou, and Sir Iain Chalmers in this week's PLoS Medicine, who also decry the continued poor quality of many of these studies. Analysing the history and growth of reviews of evidence, the authors recommend that we must now reduce unnecessary trials and prioritise truly systematic review of the literature, so that the needs of patients, clinicians, and policymakers are met. "Streamlining and innovation ...

Asian efforts in AIDS vaccine development step up

2010-09-22
Regional efforts towards an AIDS vaccine must be strengthened and harmonized, says a new article in this week's PLoS Medicine Magazine. Yiming Shao from the National Center for AIDS/STD Control and Prevention in Beijing, China and colleagues from a range of Asian and international agencies announce the formation of AVAN—the AIDS Vaccine for Asia Network—that aims to strengthen its regional efforts in finding an AIDS vaccine. The authors say that AVAN has been set up to help facilitate the development of a regional AIDS vaccine strategy that will: accelerate research ...

LAST 30 PRESS RELEASES:

Reality check: making indoor smartphone-based augmented reality work

Overthinking what you said? It’s your ‘lizard brain’ talking to newer, advanced parts of your brain

Black men — including transit workers — are targets for aggression on public transportation, study shows

Troubling spike in severe pregnancy-related complications for all ages in Illinois

Alcohol use identified by UTHealth Houston researchers as most common predictor of escalated cannabis vaping among youths in Texas

Need a landing pad for helicopter parenting? Frame tasks as learning

New MUSC Hollings Cancer Center research shows how Golgi stress affects T-cells' tumor-fighting ability

#16to365: New resources for year-round activism to end gender-based violence and strengthen bodily autonomy for all

Earliest fish-trapping facility in Central America discovered in Maya lowlands

São Paulo to host School on Disordered Systems

New insights into sleep uncover key mechanisms related to cognitive function

USC announces strategic collaboration with Autobahn Labs to accelerate drug discovery

Detroit health professionals urge the community to act and address the dangers of antimicrobial resistance

3D-printing advance mitigates three defects simultaneously for failure-free metal parts 

Ancient hot water on Mars points to habitable past: Curtin study

In Patagonia, more snow could protect glaciers from melt — but only if we curb greenhouse gas emissions soon

Simplicity is key to understanding and achieving goals

Caste differentiation in ants

Nutrition that aligns with guidelines during pregnancy may be associated with better infant growth outcomes, NIH study finds

New technology points to unexpected uses for snoRNA

Racial and ethnic variation in survival in early-onset colorectal cancer

Disparities by race and urbanicity in online health care facility reviews

Exploring factors affecting workers' acquisition of exercise habits using machine learning approaches

Nano-patterned copper oxide sensor for ultra-low hydrogen detection

Maintaining bridge safer; Digital sensing-based monitoring system

A novel approach for the composition design of high-entropy fluorite oxides with low thermal conductivity

A groundbreaking new approach to treating chronic abdominal pain

ECOG-ACRIN appoints seven researchers to scientific committee leadership positions

New model of neuronal circuit provides insight on eye movement

Cooking up a breakthrough: Penn engineers refine lipid nanoparticles for better mRNA therapies

[Press-News.org] NASA study shows desert dust cuts Colorado River flow