Foreign ozone emissions lower U.S. air quality

"It is useful to understand how much air pollution is coming from areas outside our own region, so that when we're thinking about how to cut down ozone concentrations, we can take into account what factors we have control over and what factors we don't have control over," says Tracey Holloway, a professor of environmental studies in the Center for Sustainability and the Global Environment (SAGE), who led the new study.

Unlike the protective stratospheric ozone layer, surface ozone is a pollutant and has been implicated in increased mortality rates, respiratory and cardiovascular disease, and vegetative and crop damage.

Using a computer model that analyzed global wind data and chemical emissions from various countries, the research group found that the impact of Asian and European ozone contributions varies across the country.

While previous computer modeling studies have examined ozone transportation between entire continents, often focusing on spring and summer, Holloway explains, "[Our study] is the first that has laid out the seasonality of ozone import to specific regions of the United States."

Holloway will present the group's findings today (Dec. 13) at the American Geophysical Union meeting in San Francisco.

Overall, the models showed Asian and European emissions contributed three to 18 percent of total surface ozone on a monthly average basis across the U.S.

"These air pollutants don't come with an import/export label, so it's useful to be using these models to identify what fraction is coming from individual sources," says Holloway.

The western states endured the heaviest impact, due to their proximity to Asia and the predominance of west-to-east wind currents, Holloway says. Foreign emissions contributed an annual average of 12 percent of the total surface ozone along the West Coast, but only six to ten percent along the East Coast.

Spring and fall peaks of imported ozone were evident in all regions as a result of the optimal combination of a strong jet stream across the Pacific Ocean and stability of ozone during these seasons.

Next, the group will work with high-resolution models to study how the imported pollution interacts with local and regional weather patterns and emissions.

Knowing the extent of foreign contributions can help local and federal governments develop plausible pollution and environmental policies, Holloway says. "To design effective regulations for ozone, one of the questions you want to know is how much is coming in from outside our borders that we can't control domestically," she explains.

The study's findings also suggest that reducing foreign emissions may improve U.S. air quality, a potential incentive for the federal government to promote global clean air standards, Holloway says.

Source: University of Wisconsin-Madison

Wildfires cause ozone pollution to violate health standards, new study shows
Wildfires can boost ozone pollution to levels that violate U.S. health standards, a new study concludes. The research, by scientists at the National Center for Atmospheric Research (NCAR), focused on California wildfires in 2007, finding that they repeatedly caused ground-level ozone to spike to unhealthy levels across a broad area, including much of rural California as well as neighboring Nevada.
Researchers examine impact of beetle kill on Rocky Mountain weather, air quality
Mountain pine beetles appear to be doing more than killing large swaths of forests in the Rocky Mountains. Scientists suspect they are also altering local weather patterns and air quality.
Walnut trees emit aspirin-like chemical to deal with stress
Plants in a forest respond to stress by producing significant amounts of a chemical form of aspirin, scientists have discovered. The finding, by scientists at the National Center for Atmospheric Research (NCAR), opens up new avenues of research into the behavior of plants and their impacts on air quality, and it also has the potential to give farmers an early warning signal about crops that are failing.
Study shows exposure to bad air raises blood pressure
The air people breathe while walking in the park, working in the garden or shopping downtown may be unhealthy enough to seriously spike their blood pressure, a new study suggests.
Air Quality Forecasts for China
With less than a month remaining before the Beijing Olympics, Chinese officials have introduced a series of measures to improve air quality for the Games. A new tool has been installed in the capital city to allow the Chinese to monitor the effectiveness of these efforts.
Study reveals air pollution is causing widespread and serious impacts to ecosystems
If you are living in the eastern United States, the environment around you is being harmed by air pollution. From Adirondack forests and Shenandoah streams to Appalachian wetlands and the Chesapeake Bay, a new report by the Cary Institute of Ecosystem Studies and The Nature Conservancy has found that air pollution is degrading every major ecosystem type in the northeastern and mid-Atlantic United States.
Destruction of greenhouse gases over tropical Atlantic
Large amounts of ozone – around 50% more than predicted by the world's state-of-the-art climate models – are being destroyed in the lower atmosphere over the tropical Atlantic Ocean. Published today (26th June '08) in the scientific journal, Nature, this startling discovery was made by a team of scientists from the UK's National Centre for Atmospheric Science and Universities of York and Leeds. It has particular significance because ozone in the lower atmosphere acts as a greenhouse gas and its destruction also leads to the removal of the third most abundant greenhouse gas; methane.
Perfecting a solar cell by adding imperfections
Nanotechnology is paving the way toward improved solar cells. New research shows that a film of carbon nanotubes may be able to replace two of the layers normally used in a solar cell, with improved performance at a lower cost. Researchers have found a surprising way to give the nanotubes the properties they need: add defects.

Foreign ozone emissions lower U.S. air quality

Related stories:

News discussion: