Formaldehyde and acetaldehyde change the surface of ice under polar snowpack conditions

We’re pleased to announce the publication of our latest research article as a Just Accepted manuscript in J. Phys. Chem. C.  This article is part of the John Hemminger Festschrift.

The interaction of volatile organics with ice is a major factor influencing atmospheric composition in Polar regions. We have shown for the first time that exposure to HCHO and CH3CHO induces changes in the ice surface state, including the formation of a disordered interfacial layer and opaque domains, at environmentally relevant conditions. These findings have significant implications for our understanding of the interactions of these trace gases with ice, and the interpretation of snow pit and ice core chemical records.

Kuo , M.-H., Moussa , S. G., and McNeill, V. F. Surface Disordering and Film Formation on Ice Induced by Formaldehyde and Acetaldehyde (2014) J. Phys. Chem. C, Just Accepted Manuscript.  DOI: 10.1021/jp504285z

 

New publication with collaborators at Northwestern U.

A new manuscript was published online today in Atmospheric Chemistry and Physics Discussions.  This work was the result of a collaboration with the Geiger and Thomson groups at Northwestern U. and Prof. McNeill.  The Northwestern team measured surface tension depression in aqueous aerosol mimics by isoprene oxidation products known to form secondary organic aerosol.  Surface tension depression is an indication of the formation of an organic film at the gas-aqueous interface, and has important implications for cloud formation and aerosol heterogeneous chemistry.

Climate-relevant physical properties of molecular constituents relevant for isoprene-derived secondary organic aerosol material

 

New McNeill Group Publication – Organic salt formation & impact on aerosol properties

We’re pleased to announce the publication of the final version of our manuscript, “Inorganic salts interact with oxalic acid in submicron particles to form material with low hygroscopicity and volatility” in Atmospheric Chemistry and Physics today.  The work is the result of an ongoing collaboration with the Nenes Group at Georgia Tech.  The first author, Greg Drozd, was a postdoc in the McNeill Group from 2011-2013, and he is currently at UC Berkeley.

Inorganic salts interact with oxalic acid in submicron particles to form material with low hygroscopicity and volatility
G. Drozd, J. Woo, S. A. K. Häkkinen, A. Nenes, and V. F. McNeill, Atmos. Chem. Phys., 14, 5205-5215, 2014. doi:10.5194/acp-14-5205-2014

 

Nobel Laureate Mario Molina Awarded UCSD Medal

This article in the UCSD News is a nice followup on the Mario Molina Symposium and Celebration, which was held last week at Scripps Institution of Oceanography.  Prof. McNeill has a quote:

“Mario has been an inspirational mentor and colleague to so many atmospheric chemists,” said Faye McNeill, a Columbia University professor and former student in Molina’s research group at MIT who helped organize the symposium with Prather. “The foundation of his work is truly visionary, elegant chemistry. But beyond this, Mario is a master science communicator. This has enabled him to translate atmospheric chemistry fundamentals into policy realities.”

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Mario Molina Celebration and Symposium

A symposium in honor of Prof. Mario Molina will take place next week at Scripps Institution of Oceanography in La Jolla, California.  Prof. McNeill and Prof. Kim Prather of UCSD are organizing this event in honor of Mario’s 71st birthday and his many accomplishments, including being awarded the Presidential Medal of Freedom in 2013. Mario’s colleagues and former students will be coming from all around the world to celebrate with Mario. Click here for more about the event.

Mario was Prof. McNeill’s Ph.D. advisor at MIT.  Fun fact: in the picture to the left, he is posing with the Chemical Ionization Mass Spectrometer she used for the experiments described in the following papers:

“Hydrogen Chloride-induced Surface Disordering on Ice,” VF McNeill, T Loerting, FM Geiger, BL Trout, MJ Molina. Proc. Natl. Acad. Sci. USA 103 (25) 9422-9427 (2006). link to paper

“The Interaction of Hydrogen Chloride with Ice Surfaces: The Effects of Grain Size, Surface Roughness, and Surface Disorder,” VF McNeill, T Loerting, FM Geiger, BL Trout, LT Molina, MJ Molina. J. Phys. Chem. A, 111, 6274-6284 (2007). link to paper

 

McNeill Group EOS Party Spring 2014

This weekend the group celebrated a year of big milestones with home-cooked food, chocolate fondue, and good times. Bottom picture, L-R: Yufeng, Christina, Yanyin, Hannah, Alison, VFM, Sammy, Mark, Andres, Sam, Sarah, Wanyi, Dr. Joe

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Ambient Measurements of Local NJ Brush Fire Show Increased Particle Concentrations

McNeill Group students took some ambient aerosol measurements yesterday morning, to observe any effects that the brush fire in Wheaton State Forest had on outside particle concentrations.

Our data show a nearly eight-fold increase of ambient aerosols earlier in the morning compared to the afternoon, indicating observed particles from the fire that decreased over the course of the day, as the fire was contained and emitted particles were allowed to dissipate.

Figure01-040714Between the morning and afternoon, a shift in the ambient aerosol particle size distribution was also observed. Larger particles were observed in the morning, contributing the bulk of the observed mass and leading to decreased visibility in the area due to scattering of light.

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Brush Fire in NJ leads to Decreased Visibility in NYC

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Photo credit: WNBC.

On late Sunday, April 6th, a brush fire broke out roughly 90 miles south of New York City, burning approximately 30 acres of Wharton State Forest, the largest state forest in New Jersey.

The resultant particulate matter released into the atmosphere had extremely high measured values around the Tri-state area compared to data from the previous day, resulting in decreased visibility and a noticeable scent of burning matter.