Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Atmospheric Chemistry Seminar

Chemistry of Organic Compounds in the Atmosphere and Indoor Air, by Prof. Paul Ziemann, ANYL Chem Faculty, CU Boulder, and Recent Results and Upcoming Projects Investigating Aerosol Sources, Properties, Processes, and Fate, by Prof. Jose L. Jimenez,
ANYL Chem Faculty, CU Boulder

Paul Ziemann: Laboratory studies provide much of the fundamental data on reaction kinetics, products, and mechanisms that are needed to understand atmospheric and indoor air chemistry and to develop models that are used to establish air quality regulations and predict the effects of human activities. Research in my laboratory focuses primarily on environmental chamber studies of the atmospheric chemistry of organic compounds emitted from natural and anthropogenic sources and the physical and chemical processes by which oxidized organic reaction products form aerosol particles. In addition to this we have recently conducted a number of studies of indoor air chemistry at CU. In this talk I will describe how we conduct the studies by using a diverse array of measurement techniques.

Jose Jimenez: Organic aerosols (OA) account for about 1/2 of the submicron particle mass in the atmosphere leading to important impacts on climate, human health, and other issues, but their sources, properties, and evolution remain poorly understood. In this talk I will present an overview and highlights of research on OA instrumentation, measurements, and modeling by our group over the last year, as well as of upcoming projects of potential interest to 1st year students.

Ongoing projects include global aerosol measurements and analysis as part of the NASA ATom project, which recently sampled (almost) pole-to-pole across the vertical profile. Model comparisons suggest the importance of fast OA removal channels, and a strong overestimation of primary OA in some models. Remote aerosols are very acidic with a typical pH ~ 0, which is significantly lower than predicted by global models. We are also performing a meta-analysis of urban SOA at megacities worldwide, which shows remarkably consistent results and allows us to more accurately estimate the global number of deaths due to this source. Other topics that we are working on, and that I will touch on as time permits, are RO2 chemistry in Oxidation Flow Reactors (OFR) and how it compares with large chambers and the atmosphere; gas/particle partitioning in the laboratory for different types of seed particles; the impact of different types of tubing and instruments on the measurement of intermediate volatility and semivolatile species; the sources and budget of organic carbon in indoor air; and the development of fast SOA parameterizations for global and climate models.

Some upcoming projects include include the study of emissions and chemical evolution of smoke from real fires in the western US with the NASA DC8 (NASA FIREX-AQ) with AMS and soft-ionization EESI-TOF; an upcoming indoor campaign at a weight room at the CU Athletic Dept; and potentially the CalNexT ground-based study of urban chemistry in Los Angeles (which follows up on the highly successful CalNex-2010 study).


Monday, October 22, 2018
12:00pm to 1:00pm


Ekeley S274

Event Type



Anne Handschy,