Photochemical Oxidation/Products Group

 

 

The Photochemical Oxidation/Products (POP) group performs measurements to address questions in three general research areas:  photochemistry, sulfur chemistry, and aerosol nucleation and growth.

 

Measurements include:

 

Gas Phase	Aerosol Phase
OH, H2SO4, MSA, HNO3, DMSO, DMSO2, ambient ion and ion clusters, NH3	ultrafine aerosol nitrate, sulfate, and ammonium, oxidized organics

 

Specific scientific questions of current interest include:

• How well is OH production and loss understood particularly in unique environments such as Antarctica and anthropogenic plumes?
• What are the remote marine oxidants responsible for the formation of gas phase sulfuric and methanesulfonic acids and DMSO at night?
• How do MS/sulfate ratios observed in the Antarctic ice depend on DMS oxidation chemistry and transport over the polar plateau?
• What are the primary chemical compounds responsible for nucleation and growth?
• Does ammonia have a unique role in controlling particle growth?
• Why does nucleation observed in the lower troposphere occur at a much lower concentration and with a weaker functional dependence on H₂SO₄ than predicted by classical theory?

 

New Research Thrusts:

 

• Development of an aircraft based ammonia measurement capability
• Characterize the chemical composition of ambient ultrafine aerosols.  Of particular of interest are insoluble organic species
• Develop new chemical ionization ion trap mass spectrometric measurement technique for a broad range of oxygenated biogenic and anthropogenic compounds

 

What’s New?

 

• Graduate student Matt Dunn is building a web site describing our particle size distribution measurements at our lab here in Boulder, CO. Click here to view his site.
• View the latest particle size distribution from outside of our laboratory in Boulder, CO. Click here to view. Archived data is also available for viewing.
• November 5, 2003: Added poster on Mexico City nanoparticle size distributions (3-50 nm mobility diameter), presented by Matt Dunn at the 2003 meeting of the American Association for Aerosol Research in Anaheim, CA.  Click here to view.
• April 30, 2003: Added poster on TDCIMS measurements of the chemical composition of 5-20 nm diameter aerosol during the Atlanta-ANARChE campaign.  Click here to view.

 

last revised: January 27, 2004; for questions/comments: jimsmith@ucar.edu.