CSU scientist simplifies aerosols for modeling

May 26, 2010
This photo of Mexico City, taken in 2006, was part of the MILAGRO or Megacity Initiative: Local and Global Research Observations field campaign led by the National Center for Atmospheric Research. Scientists around the globe, including atmospheric chemists at Colorado State University, are studying aerosols and their contribution to pollution in the atmosphere. Credit: Sasha Madronich at the National Center for Atmospheric Research

The large number of tiny organic aerosols floating in the atmosphere - emitted from tailpipes and trees alike - share enough common characteristics as a group that scientists can generalize their makeup and how they change in the atmosphere.

The groundbreaking research by Colette Heald, assistant professor in the Department of Atmospheric Science at Colorado State University, was highlighted this month on the cover of the American Geophysical Union's prestigious .

"The hope is that we can start to accurately represent organic aerosols in climate models so we can address how they impact climate and air quality, and particularly the issue of how much is natural and how much comes from human activities," Heald said. "What we're really trying to get at is the composition - what's in the , how is it changing and where does it have an environmental impact? Many of the compounds in the atmosphere are really short lived, so the picture changes quickly."

The atmosphere contains many different kinds of aerosols such as dust and sulfate as well as organic aerosols. These organic aerosols come from many different sources, including fossil fuel emission and wildfires. , bacteria and pollen are among the major biologically produced organic . Further complicating the picture are atmospheric gases that change over time and can become aerosols in the atmosphere.

But for , the differences may not matter as much as previously thought.

Heald plotted hydrogen-to-carbon and oxygen-to-carbon ratios from observations of aerosols in the laboratory and in field experiments from such places as , the Amazon and Los Angeles. Even though the studies looked at different aerosols from very different environments, she could classify them as a group based on their overall oxygen and hydrogen content.

Oxygen also plays a role in changing the chemical makeup of aerosols. The longer aerosols have been in the atmosphere, the more their composition has been altered- a process called oxidation.

As a result, the observed differences Heald found are plotted along a trajectory - from the freshest, most recent emissions from a diesel truck, for example, to particles that have been in the atmosphere for several days.

"In recent years, we've realized there are thousands and thousands of different organic species in the atmosphere," Heald said. "With this study, we've found a simple way to describe all that complexity."

"It's still very important that we understand the different individual species in our atmosphere, but from a modeling perspective, it gives us hope we can simplify our entire description of organic aerosol composition."

Explore further: Magnitude-7.2 earthquake shakes Mexican capital

Provided by Colorado State University

2.3 /5 (3 votes)

Related Stories

NASA probes the sources of the world's tiny pollutants

Jan 30, 2007

Pinpointing pollutant sources is an important part of the ongoing battle to improve air quality and to understand its impact on climate. Scientists using NASA data recently tracked the path and distribution ...

The mystery of particles

Jun 19, 2009

Particles cool down the climate, but to which extent? This has remained an unanswered question for scientists. A new article in Science by Gunnar Myhre at CICERO, Norway, brings the scientific community a step closer to sol ...

Summer haze has a cooling effect in southeastern United States

May 18, 2009

(PhysOrg.com) -- Global warming may include some periods of local cooling, according to a new study by researchers at the University of California, Berkeley. Results from satellite and ground-based sensor data show that sweltering ...

Recommended for you

Magnitude-7.2 earthquake shakes Mexican capital

23 hours ago

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

User comments : 0

More news stories

Magnitude-7.2 earthquake shakes Mexican capital

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

LinkedIn membership hits 300 million

The career-focused social network LinkedIn announced Friday it has 300 million members, with more than half the total outside the United States.

Treating depression in Parkinson's patients

A group of scientists from the University of Kentucky College of Medicine and the Sanders-Brown Center on Aging has found interesting new information in a study on depression and neuropsychological function in Parkinson's ...

Sun emits a mid-level solar flare

The sun emitted a mid-level solar flare, peaking at 9:03 a.m. EDT on April 18, 2014, and NASA's Solar Dynamics Observatory captured images of the event. Solar flares are powerful bursts of radiation. Harmful ...