Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Study: Acidic surfaces on atmospheric aerosols greatly increase secondary aerosol formation


Atmospheric particles that become acidic through exposure to such pollutants as sulfuric acid can lead to vast increases in the formation of secondary organic aerosols, a new study indicates. Such aerosols are major components of the unsightly haze that hangs over cities and oil refineries and even affects otherwise pristine U.S. national parks.

A report on the research appears in Friday’s (Oct. 25) issue of the journal Science. Authors, all at the University of North Carolina at Chapel Hill, are Dr. Myoseon Jang, research associate; doctoral students Nadine M. Czoschke and Sangdon Lee; and Richard M. Kamens, professor of environmental sciences and engineering at the UNC School of Public Health.

"We think this exciting work is potentially very important and so do other scientists we have discussed it with across the United States," said Kamens. "What Dr. Jang has done in our laboratory was to discover an acid-catalyzed process that brings about secondary organic aerosol formation. "She also has found that this under-appreciated reaction may generate five to 10 times more aerosol in the atmosphere than we previously thought," he said. "It appears to explain a number of different kinds of phenomena that lead to aerosol formation."

Jang’s "ground-breaking" new research involves testing aerosols in reaction chambers and large outdoor smog chambers and determining what happens to them under varying experimental conditions, Kamens said.

In the new work, scientists introduced fine inert particles known as seed aerosols into Teflon film reaction chambers, he said. Into some chambers they injected identical particles coated with 2 percent to 5 percent sulfuric acid, which is about the same level found on tiny bits of floating diesel soot.

"What they did then was to introduce into the gas phase atmosphere of the chambers aldehydes and alcohols," Kamens said. "Dr. Jang found that when the aldehydes and alcohols were present, there was a huge increase in the amount of aerosol that formed."

Studies with a variety of different aldehydes, which are formed in the atmosphere by oxidation of emitted hydrocarbons, revealed that some aldehydes derived from aromatic compounds were far more reactive in producing aerosols than scientists believed. Aromatic compounds come largely from automobile and other exhausts, while trees generate massive amounts of terpenoid hydrocarbons, which also form aldehydes and particles in the atmosphere subject to similar acid-catalyzed aerosol-producing reactions.

Jang’s discovery appears to fill an important hole in scientists’ understanding of atmospheric chemistry, Kamens said. Her data also mirrors natural data collected by a Rutgers University team in the Appalachians’ Smoky Mountains under the direction of Dr. Barbara Turpin.

"People from NOAA -- the National Oceanic and Atmospheric Administration -- got very excited about this work at a recent aerosol research meeting in Charlotte," he said. "That was because it seems to explain atmospheric reactions going on over Houston, where refineries produce very large emissions of volatile organic compounds and also sulfur dioxide.

"Using Dr. Jang’s theory and findings, they immediately thought that what has been happening there was that sulfur dioxide was being oxidized as sulfuric acid. Then the sulfuric acid was acid-catalyzing organic reactions in the plume over the petroleum refineries to form huge, huge bursts of particles that nobody really understood before."

The UNC experiments should lead to new insights into global warming, photochemical reactions and weather and, possibly, some useful manipulation of them, Kamens said. They also could have important implications for pollution control and health.

"Environmental Protection Agency researchers also have said they are very interested in this work, and we’re going to share our information with them soon," he said.

Mathematical models the team is creating will help them predict what would happen in the atmosphere in response to lowering volatile organic emissions and other pollutants from cars, refineries and other sources, the scientist said.

The National Science Foundation’s Atmospheric Chemistry Division and the EPA’s STAR (Science to Achieve Results) program supported the exploratory studies with grants to Kamens’ research group.

Note: Kamens and Lee can be reached at (919) 966-5452 and 966-3861, respectively, or and

UNC News Services

David Williamson | EurekAlert!

More articles from Earth Sciences:

nachricht Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>