Posted on 12/14/2007 3:28:14 PM PST by blam
Tiny Dust Particles From Asian Deserts Common Over Western United States
ScienceDaily (Dec. 14, 2007) — It has been a decade since University of Washington scientists first pinpointed specific instances of air pollution, including Gobi Desert dust, traversing the Pacific Ocean and adding to the mix of atmospheric pollution already present along the West Coast of North America.
Now a UW researcher is finding that dust from the Gobi and Taklimakan deserts in China and Mongolia is routinely present in the air over the western United States during spring months.
"We are interested in Asian dust that comes across the Pacific because particles can have an impact on health, as well as on visibility," said Emily Fischer, a UW doctoral student in atmospheric sciences.
"Most previous work has been very event specific, but this research looks at how the average background aerosol concentrations vary on a year-to-year basis."
Aerosols are tiny particles -- such as dust, grains of sea salt, soot from fossil fuel combustion and smoke from forest fires -- suspended in the air. Many of the aerosols are comparatively large, as much as 10 microns, which still is less than the width of a human hair.
Fischer found that in years with large Asian dust storms there was an increase in particles of 2.5 microns or less in the air over the western United States. Particles that small can be inhaled more deeply into the lungs and so are a greater health concern.
"Local pollution makes the biggest contribution to poor air quality in cities, but my study is looking at aerosols in remote regions like national parks," she said. "In these places dust can be a larger contributor to the total aerosol concentrations because there is little local pollution. While some of the dust pulses from Asia are small, some of them can be very large."
Fischer used two sets of data, gathered during March, April and May from 1998 through 2006, to correlate the dust kicked up in storms over Asian deserts and the appearance of dust in air over the western United States. She looked at dust levels in the air columns directly over the deserts, recorded by NASA satellites, and then paired that information with air quality data from ground stations in rural areas of the western United States for the same period.
For the dust detected at ground stations in the United States, Fischer also looked for -- and found -- evidence of calcium, which is a tracer for desert dust.
"The calcium lends more confidence to our conclusion," she said.
While the results of the research are not unexpected, they provide supporting evidence that particles of 2.5 microns or smaller appear in higher concentrations in the western United States in years when there are high dust concentrations over Asian deserts.
"The transport of dust across the Pacific is not a new phenomenon," Fischer said. "But we are just beginning to understand it and quantify it on a year-to-year basis instead of on a case-by-case basis.
"We know that just having dust over Asia doesn't mean that it's going to come here. There is the transportation part of the puzzle, which I'm working on now. But we already know that some years are more favorable than others for dust to be transported across the Pacific."
The research is being presented at this year's annual meeting of the American Geophysical Union in San Francisco.
Fischer's doctoral adviser is Dan Jaffe, a University of Washington, Bothell, atmospheric scientist who was the first to trace air pollution from Asia as it crossed the North Pacific. Jaffe is a collaborator on Fischer's research, along with Christina Hsu and Myeong-Jae Jeong of NASA's Goddard Space Flight Center in Maryland and Sunling Gong of Environment Canada.
Adapted from materials provided by University of Washington.
"Many of the aerosols are comparatively large, as much as 10 microns, which still is less than the width of a human hair."
The average Caucasian hair diameter is about 100 microns.
A few years ago SoCal was covered by red dust from the Gobi Desert.
True, the Chinese planted over 1 billion trees to slw much of this down. I believe this is a 1935 study.
We get airborne stuff from Asia here in Interior Alaska every day. The color and quality varies depending what is on fire over there. If it is Indonesia it is acrid blue, if Mongolia it is brown clouds, if it is Chinese it is gray smoke. Always something, and it started about 20 years ago.
ATTENTION EVIROWBOZO’S, THE POLUTION IN SOUTHERN CALIFORNIA is FROM CHINA, SOMEONE ALERT “ARNOLD”.
Billions of Trees Planted, and Nary a Dent in the Desert
I read an article this week that the tree were all dying.
Just checked the date —— June 12, 13, 2003. My search showed that the red dust went all the way to Europe.
This dust transfer probably has been going on for 10’s of thousands of years.
Yup. Orange dust...used to get on my car when I lived in Melbourne, Florida.
Too late to alert “Arnold”! He’s in Jerry Brown’s camp of
Watermelon Freaks.
Must be due to Al Gore more interested in taxing us then fixing the planet.
Sounds like a good reason to avoid nuking anybody over there. Radioactive dust would blow back to us.
The Los Angeles City Council this year gave 4 million trees away.
They can only account for 285 as to who got them and where they are planted.
LA has a useless Mayor.
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