Glassy solid particles can facilitate long-distance atmospheric transport of hazardous organic pollutants
Secondary organic aerosols (SOA) are formed upon oxidation of volatile organic compounds in the atmosphere. They account for a large fraction of fine particulate matter and have a strong influence on regional and global air quality.
Organic particles are ubiquitous in air pollution. The new study reveals when and where these particles are liquid, viscous or solid. The picture shows an extreme haze event over Beijing and others cities in China in January 2013.
Source: NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response
This chart shows how the phase state of secondary organic aerosols changes depending on altitude and temperature. Whether the particles are liquid, semisolid (viscous) or solid (glassy) has strong implications for their chemical fate, long-range transport and their influence on the formation on clouds.
Source: Manabu Shiraiwa
Traditionally, SOA particles were assumed to be oily liquid droplets. Depending on chemical composition, temperature, and humidity, however, SOA particles can also adopt a glassy solid phase state, as revealed in recent studies. Whether the particles are liquid or solid makes a big difference for how they interact with clouds and trace gases and how they can influence climate and public health.
So far, however, it was unclear if and where in the atmosphere SOA particles are liquid or solid. A new study of an international team of scientists including researchers from the Max Planck Institute for Chemistry in Mainz and the University of California in Irvine, USA, provides insight into the global distribution of organic particle phase state in the atmosphere.
“We found out? that SOA particles are mostly liquid near the Earth’s surface, and glassy in the rest of the atmosphere”, explains Manabu Shiraiwa, first author of the study recently published in the Open Access journal “Nature Communications”. Shiraiwa, a former group leader at the MPI for Chemistry in Mainz, works now as an Assistant Professor at the Chemistry Department at the University of California, Irvine.
Glassy SOA particles can shelter organic pollutants from degradation by atmospheric oxidants, which explains why high concentrations of such pollutants are observed not only close to anthropogenic sources but also in remote marine and polar regions.
Whether SOA particles are glassy or liquid, however, depends strongly on their chemical composition and on ambient temperature, and relative humidity. Accordingly, the molecular composition and related physicochemical properties of SOA need to be known for a reliable assessment of particle phase state and effects, but they were not well constrained in earlier studies.
“For the first time, we could implement a sophisticated molecular description of the physical and chemical properties of SOA particles in a state-of-the-art global model to compute the spatial and temporal variability of SOA phase state in the atmosphere”, says Ulrich Pöschl, director of the Multiphase Chemistry Department at the MPI for Chemistry. Jos Lelieveld, director of the Atmospheric Chemistry Department at the Mainz´ institute, adds that “further studies are planned to quantify the effects of SOA phase state on clouds, climate, air quality and public health”.
“Global distribution of particle phase state in atmospheric secondary organic aerosols”: Manabu Shiraiwa, Ying Li, Alexandra P. Tsimpidi, Vlassis A. Karydis, Thomas Berkemeier, Spyros N. Pandis, Jos Lelieveld, Thomas Koop, Ulrich Pöschl, Nature Communications 2017, DOI: 10.1038/ncomms15002
Prof. Dr. Manabu Shiraiwa
Department of Chemistry, University of California, Irvine, CA 92697, USA
Prof. Dr. Ulrich Pöschl
Max Planck Institute for Chemistry, Mainz
Director, Multiphase Chemistry Department
Phone: +49(0)6131 305 7000
Prof. Dr. Jos Lelieveld
Max Planck Institute for Chemistry, Mainz, Germany
Director, Atmospheric Chemistry Department
Phone: +49-6131-305 4000
Dr. Susanne Benner | Max-Planck-Institut für Chemie
Individual Receptors Caught at Work
19.10.2017 | Julius-Maximilians-Universität Würzburg
Rapid environmental change makes species more vulnerable to extinction
19.10.2017 | Universität Zürich
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
19.10.2017 | Materials Sciences
19.10.2017 | Materials Sciences
19.10.2017 | Physics and Astronomy