Observations

Laboratory Kinetics Group

Group Members:

Geoff Tyndall (group lead): tyndall@ucar.edu
John Orlando: orlando@ucar.edu

General Scientific Objectives:

  • Understand the oxidation mechanisms of organic compounds in the atmosphere.
  • Study the reactions and cycling of atmospheric free radicals (HOx, NOx and halogens).


Available Research Tools:

  • Stainless steel environmental chamber, 50 L volume, temperature-regulated, interfaced to an FTIR spectrometer and GC-FID system (for mechanistic studies and relative rate coefficient determinations).
  • Teflon chamber, 10 cubic meters, for atmospheric organic mechanism studies.  In addition to basic chamber characterization and control instrumentation (flow rates, ozone, temperature, particle size distribution, relative humidity, pressure, and light control), gas-chromatography (GC), proton-transfer reaction – mass spectrometry, and chemical ionization mass spectrometers (CIMS) are available for chemical characterization of chamber contents.
  • UV/visible absorption spectrometer system.
  • Flash photolysis system – Pulsed excimer laser; near-IR diode laser absorption system for time-resolved detection and kinetic studies.


Major Current Research Foci:

  • Oxidation mechanisms of and OH/Cl/NO3 site-of-attack on oxygenated and multifunctional organic compounds.
  • Reactions of organic peroxy radicals (e.g., reactions with HO2, unimolecular processes, formation of organic nitrates).
  • Development and use of the GECKO-A fully explicit chemical mechanism generator.
  • Reaction mechanism development; structure-reactivity relationships.
  • Impact of VOC emissions from wildfires on air quality and climate.
  • Oxidation mechanisms for biogenic compounds.

 

Photo of the Laboratory Kinetics group

Figure 1. (left to right) Geoff Tyndall, ACOM SOARS protégé Cherelle Blazer, and John Orlando conducting experiments in the FTIR lab.

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ACOM | Atmospheric Chemistry Observations & Modeling