Above, NASA, 6/2001, scroll down: "This TOMS [Total Ozone Mapping Spectrometer] image shows a record-setting Asian dust cloud beginning its journey east across the Pacific. Click on the image to view a 440 kb animation of the dust cloud migrating to North America. Remember that as the dust disappears from the satellite's view, it's raining out of the air onto the ocean and the land. See a similar Asian dust cloud from 1998 in this animation,"
science.nasa.gov
""The ozone on the West Coast in a few years will be controlled not by California and Oregon," Schnell (NOAA) says. "It will be controlled by China."" Nov. 2006
"During these surges, the air entering the West Coast can have pollution concentrations as high as 75 percent of federal air quality standards, Jaffe said." 5/17/2001, NASA
May 2001 article
5/17/2001, "The Pacific Dust Express," science.nasa.gov
"A dust cloud from China crossed the Pacific Ocean recently and rained Asian dust from Alaska to Florida."
"Scientists recently used NASA satellites to track a cloud of dust up to 2,000 km long as it left Asia, drifted across the Pacific Ocean, and traversed North America from Alaska to Florida, raining dust and possibly pollutants over the continent.
Dust clouds blowing east from Asia are a common occurrence in the springtime, but last month's million-ton dust cloud was surprisingly large and long-lasting.
"In terms of area covered, this was the largest dust storm we've observed in the Northern Hemisphere (since 1979). This was massive," said Jay Herman, principal investigator for aerosols for NASA's Total Ozone Mapping Spectrometer (TOMS), a satellite-based instrument commonly used by scientists to track aerosols (tiny airborne particles like dust or smoke)....
These springtime dust storms give visible evidence of a "conveyor belt in the sky" that ferries air from Asia to North America in the spring. Invisible pollutants are also carried across the Pacific Ocean by this conveyor, according to Daniel Jaffe, professor of atmospheric sciences at the University of Washington.
Based on air quality measurements at Cheeka Peak at the westernmost tip of Washington state and later airplane-based measurements, Jaffe's research group has shown that a steady trickle of air pollution comes across the Pacific from Asia-at least in the spring-punctuated by a surge of pollutants once or twice a month.
These surges are presumably due to the wholesale movement of air from Asian urban areas across the Pacific. This prevents the pollutants from being diluted by mixing with cleaner air. During these surges, the air entering the West Coast can have pollution concentrations as high as 75 percent of federal air quality standards, Jaffe said.
Scientists won't know the exact make up of last month's cloud until chemical analysis of dust samples collected from the cloud can be completed.
The dust cloud originated between April 6th and 9th when strong winds from Siberia kicked up millions of tons of dust from the Gobi and Takla Makan deserts in Mongolia and China, respectively. Air currents then carried the dust east. The leading edge of the cloud reached the U.S. West Coast on April 12th, and 2 days later it had crossed the East Coast shoreline and began heading out into the Atlantic.
By the time the dust cloud finally disappeared from satellite images on April 24, it had traversed two-thirds of the Atlantic toward England.
To onlookers in North America, the vast dust cloud appeared as a hazy white tint to the sky (due to the scattering of all wavelengths of sunlight by the dust particles), and in some places the dust fell to ground level and blanketed cities in a thin haze.
"You couldn't miss it," said Duane Hilton, a resident of Bishop, California, where the cloud descended in April. "We usually have 50 miles visibility, but at one point you could see dust in the air looking at objects just 8 to 10 feet away."...
In the spring, conditions in the atmosphere over Asia are ripe for both massive dust storms and wholesale movement of large volumes of air across the Pacific Ocean. The combination of dry soils and high winds leads to a spurt of dust storm activity, which coincides with strong winds that carry the dust over the Pacific."...
Below, NASA map, Asia dust leaving April 6 reached Midwest US by April 13:
"Above: While much of the dust cloud remains over the Pacific Ocean, the leading edge has reached as far east as the American Midwest by April 13. Images such as this one are a principal tool for scientists who study aerosols." science.nasa.gov, 2001
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June 2001 article:
6/26/2001, "All the World's a Stage...for Dust," science.NASA.gov
"Northern spring also brings massive dust clouds blowing east over the Pacific Ocean from China and Mongolia. The largest Asian dust cloud on record blew all the way across North America earlier this year, traveling as far east as the mid-Atlantic Ocean before finally disappearing from view.
"The huge amount of dust blowing off Asia recently is kind of a new phenomenon," Herman says. "It's apparently due to increased desertification brought about by a change in the dryness of the area and increased land use."...
The raining of dust into the Pacific Ocean may be important for the productivity of fisheries in the North Pacific, an important source of seafood for much of the world. Photosynthetic microbes in the top layer of the ocean form the foundation of the food chain. Often the concentration of dissolved mineral nutrients (particularly iron) controls the abundance of these microbes. Some of the minerals in the dust might help boost microbe populations and, therefore, fish populations. Scientists are still working to verify this effect, however.
Airborne dust clouds can also affect local weather by suppressing rainfall. Cloud droplets form around the minute dust grains, but some kinds of dust limit how big these droplets can become. Because droplets must reach a certain size before they'll fall to Earth as rain, dust clouds can leave dry weather in their path.
In addition to dust, the TOMS instrument detects
volcanic ash, pollutants, smoke, ozone concentrations and ultraviolet light intensities. Most of these data are available online in near real-time."...
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Below, 2011 and 2006 articles:
3/18/2011, "Made in China: Our Toxic, Imported Air Pollution," Discover, by David Kirby, (April 2011 issue)
"Mercury,
sulfates, ozone, black carbon, flu-laced desert dust. Even as America
tightens emission standards, the
fast-growing economies of Asia
are
filling the air with hazardous components that
circumnavigate the
globe."
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These contaminants are implicated in a long list of health problems, including neurodegenerative disease, cancer, emphysema, and perhaps even pandemics like avian flu. And when wind and weather conditions are right, they reach North America within days. Dust, ozone, and carbon can accumulate in valleys and basins, and mercury can be pulled to earth through atmospheric sinks that deposit it across large swaths of land....
...........
p. 7, "Perhaps the most counterintuitive traveling contaminant is ozone, commonly associated with ground-level pollution in cities. Volatile organic compounds, carbon monoxide, and nitrogen oxides from Asian cars and industry mix in the atmosphere as they cross the Pacific Ocean and convert in sunlight into ozone, a main ingredient in smog, Jaffe explains. When air with high ozone concentrations touches down in North America, it can pose the classic dangers of urban smog: heart disease, lung disease, and death.
.........
Jaffe recently coauthored a paper on Asian ozone coming to America. It found that ozone levels above western North America creep upward every spring. “When air was coming from Asia, the trend was strongest. That was the nail in the coffin,” Jaffe says. “The increase was estimated at 0.5 part per billion [ppb] per year. But that’s huge. In 10 years that’s another 5 ppb. Let’s say the EPA orders a 5 ppb reduction and we achieve that, and yet, because of the growing global pool, in 10 years that gets wiped out. We’ll have to keep reducing our emissions just to stay even.”...
p. 9, "Asian mercury can reach western North America in as little as four days. Satellite images and atmospheric models such as these have helped Jaffe demonstrate how mercury and other emissions from China feed into a complex network of air currents that distribute pollutants across the globe."...
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2006 article:
""The ozone on the West Coast in a few years will be controlled not by California and Oregon," Schnell (NOAA) says. "It will be controlled by China." The incoming pollution bucks a U.S. trend toward cleaner skies and water...."There's more mercury deposited in this country from outside our borders than from inside our borders," says Richard Scheffe, U.S. Environmental Protection Agency senior science adviser."...(subhead, "Impact on cleanup")
4/13/2008, "China's mercury flushes into Oregon's rivers," The Oregonian, Shelby Wood, Richard Read; richardread@news.oregonian.com"...........
"From the Oregonian of Nov. 24, 2006"
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"Every five or six days, the winds flush out eastern China, sending dust and pollutants such as ozone precursors high over the Pacific, says Russ Schnell, observatory and global network operations director for the National Oceanic and Atmospheric Administration.
"The ozone on the West Coast in a few years will be controlled not by California and Oregon," Schnell (NOAA) says [in 2006]. "It will be controlled by China." The incoming pollution bucks a U.S. trend toward cleaner skies and water....
"Our best estimates indicate that there's more mercury deposited in this country from outside our borders than from inside our borders," says Richard Scheffe, U.S. Environmental Protection Agency senior science adviser.
Mercury is just one of the foreign pollutants that scientists are tracking. At least one-third of California's fine particulate pollution --known as aerosol --has floated across from Asia, says Steve Cliff, an atmospheric scientist at the University of California at Davis.
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"In May this year, almost all the fine aerosol present at Lake Tahoe came from China," says Tom Cahill, a UC Davis emeritus professor of atmospheric sciences. "So the haze that you see in spring at Crater Lake or other remote areas is in fact Chinese in origin."
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Cliff (UC Davis) says China's growing contribution will complicate U.S. efforts to meet annual average emissions standards."...
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