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Climate: Bioparticles in dusty air may be key to rain and snow formation

Tiny bioparticles in atmospheric dust play a big role in the formation of raindrops and snowflakes. bberwyn photo.

Tiny bioparticles in atmospheric dust play a big role in the formation of raindrops and snowflakes. bberwyn photo.

Researchers starting to take nuanced look at chemical composition of aerosols

Staff Report

FRISCO —Scientists have long known that tiny grains of airborne dust are key players in the formation of rain and snow, driving precipitation patterns across the drought-stricken western U.S. and other areas.

New research suggests that  the exact chemical make-up of that dust, including microbes found in it, is the key to how much rain and snow falls from clouds.  The information could help better predict rain events, as well as explain how air pollution from a variety of sources influences regional climate in general.

“We’ve learned that not all of the particles in the air at high altitudes have the same influence on clouds. We’re starting to think that these differences contribute to how rain gets distributed,” said Dr. Kim Prather, who presented her findings at the 248th National Meeting & Exposition of the American Chemical Society last week in San Francisco. Continue reading

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Climate: Historic paintings offer atmospheric clues

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Many of J.M. Turner’s famed impressionist sky scenes were painted shortly after the 1815 eruption of the Tambora Volcano in Indonesia.

Study traces pollution levels by analyzing 500 years of art

Staff Report

FRISCO — Looking closely at some of the world’s great paintings from the past 500 years has enabled scientists to track the history of atmospheric pollution, based on the colors the artists used to depict the sky.

For example, when he Tambora volcano in Indonesia erupted in 1815, painters in Europe could see the colors of the sky changing. The volcanic ash and gas spewed into the atmosphere traveled the world and, as these aerosol particles scattered sunlight, they produced bright red and orange sunsets in Europe for up to three years after the eruption.

Continue reading

Forest fumes play big role in global climate

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What’s the role of coniferous trees in regulating climate?

Fast growth of particles from pine tree fumes surprises researchers

By Summit Voice

FRISCO — Forests may play a much bigger role in global climate than previously believed. In addition to cycling carbon, it appears that gases wafting from conifers quickly form small particles that can reflect sunlight and promote cloud formation, according to a new study that looked at forest aerosols at the molecular level.

“In many forested regions, you can go and observe particles apparently form from thin air. They’re not emitted from anything, they just appear,” said Joel Thornton, a University of Washington associate professor of atmospheric sciences. Continue reading

Study helps unravel the secret life of clouds

Air pollution can be a big factor in development of thunderclouds

Thundercloud over Peak 1

Air pollution can have a significant impact on the development of thunderclouds, causing cloud remnants to persist longer. bberwyn photo.

FRISCO — Air pollution can have a significant effect on the development of thunderhead clouds, causing the cloud remnants to persist high in the atmosphere long after thunderstorms dissipate. This, in turn, can affect daily temperature ranges, as the lingering clouds partially cool the Earth during the day with their shadows, but trap heat to keep nighttime temperatures warmer.

The new study, from the Department of Energy’s Pacific Northwest National Laboratory, helps answer long-running questions about how airborne pollutants affect climate warming. The findings will help provide a gauge for the accuracy of weather and climate models.

“This study reconciles what we see in real life to what computer models show us,” said atmospheric scientist Jiwen Fan. “Observations consistently show taller and bigger anvil-shaped clouds in storm systems with pollution, but the models don’t always show stronger convection. Now we know why.” Continue reading

Aerosols still a big missing piece of climate puzzle

sdfgsdfNew study suggests natural aerosols may be a bigger factor than previously thought

By Summit Voice

FRISCO — In their quest to better understand the role of aerosols in the Earth’s climate, researchers may have to try and find the cleanest parts of the atmosphere.

Knowing to what degree both human-caused and natural aerosols mask the effects of heat-trapping greenhouse gases is crucial to making accurate climate predictions, according to a new study that assessed 28 factors that could affect the uncertainties in cloud brightness.

Natural aerosols, such as emissions from volcanoes or plants, may contribute more uncertainty than previously thought to estimates of how the climate might respond to greenhouse gas emissions. Continue reading

Climate: Tracking atmospheric aerosols

New satellite data shows volcanoes are a bigger factor than industrial emissions, at least high in the atmosphere

Alaska's Redoubt Volcano erupting in 1990. Photo courtesy USGS/R.J. Clucas.

Alaska’s Redoubt Volcano erupting in 1990. Photo courtesy USGS/R.J. Clucas.

By Summit Voice

FRISCO — Scientists have long known that aerosols can have a major effect on climate, and with measurements from sensitive satellite-based instruments, they’re getting a better handle on the formation, distribution and sources of various sulfur compounds in the atmosphere.

In a new study, researchers with the Karslruhe Institute of Technology say they’ve compiled one of the most comprehensive overview of sulfur dioxide measurements.

“Sulfur compounds up to 30 km altitude may have a cooling effect,” said KIT researcher Michael Höpfner, explaining that sulfur dioxide and water vapor react to sulfuric acid that forms aerosols, that reflect solar radiation back into universe. Continue reading

Climate: Does atmospheric dust cause warming or cooling?

NASA research adds to understanding of dust events

NASA often captures images of dust storms from orbiting satellites, but one recent study looked at the dust from the ground up, finding that the events can have localized warming effect.

By Summit Voice

SUMMIT COUNTY — Desert dust storms blowing across the Colorado Rockies from the Southwest have already been implicated as a factor  in earlier snowmelt; now, new research by NASA suggests that airborne dust can have a significant, localized effect on atmpospheric temperatures.

The study was conducted in a semi-arid region between China’s Taklimakan and Gobi deserts, where the NASA team set up a field research site in Zhangye. Using an array of upward-looking instruments for measuring airborne dust particles, they assessed the impact of dust storms from the adjacent deserts. 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

Climate: smaller volcanoes found to affect upper atmosphere

A NASA satellite captures a view of the smoke billowing from the Nabro Volcano in Ethiopia during a June 2011 eruption.

New study to help inform climate models

By Summit Voice

SUMMIT COUNTY — Using data from sensitive satellite instruments, researchers at the University of Saskatchewan have determined relatively small volcanic eruptions can affect climate on a global level, as aerosols from the eruptions are transported into the upper levels of the atmosphere by weather systems like monsoons.

“If an aerosol is in the lower atmosphere, it’s affected by the weather and it precipitates back down right away,” said Adam Bourass, with university of Saskatchewan’s Institute of Space and Atmospheric Studies. “Once it reaches the stratosphere, it can persist for years, and with that kind of a sustained lifetime, it can really have a lasting effect,” Bourass said, explaining that the particles scatter incoming sunlight, thus cooling the Earth’s surface. Continue reading

Environment: Air pollution altering weather patterns

A 2006 image from NASA's Terra satellite shows haze over the East Coast of the U.S.

Aerosols affect cloud formation, height and thickness; changing precipitation frequency and intensity

By Summit Voice

SUMMIT COUNTY — Shortly after another recent study found that pollution may be intensifying hurricanes in the Arabian Gulf, University of Maryland scientists said increases in air pollution can intensify droughts and precipitation.

The research provides the first clear evidence of how aerosols, like soot, dust and other small particles in the atmosphere can affect weather and climate. The findings have important economic and water resource implications for regions across the United States and around the world, said the researchers and other scientists.

“Using a 10-year dataset of extensive atmosphere measurements from the U.S. Southern Great Plains research facility in Oklahoma (run by the Department of Energy’s Atmospheric Radiation Measurement program), we have uncovered, for the first time, the long-term, net impact of aerosols on cloud height and thickness, and the resultant changes in precipitation frequency and intensity,” says Zhanqing Li, a professor of atmospheric and oceanic science at Maryland and lead author of the study. Continue reading

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