Chemical Characterization of Photolytic Aging Processes in Atmospheric Aerosols
EMSL Project ID
49372
Abstract
Secondary organic aerosol (SOA) represents a large fraction of total atmospheric aerosol and therefore is important for climate, however, the effect of SOA on radiative forcing is uncertain. Results from laboratory and modeling studies suggest that condensed-phase photolysis may have an important influence on the composition and lifetime of atmospheric SOA. However the rate of this process, its dependence on SOA chemical composition and particle viscosity, and its implications for the atmospheric aerosol lifecycle are poorly understood at present. Here, experiments combining online analysis of the ensemble properties of aerosols using aerosol mass spectrometry with off-line analysis at EMSL of (1) the molecular composition using ultra high resolution mass spectrometry, (2) the functional group distribution using FTIR and Raman, and (3) the physical properties using scanning electron microscopy will be carried out for aerosol samples aged via photolysis in a chamber for extended periods of time. These measurements will give insights into changes in the chemical composition as a result of photolysis in an environmental chamber as well as information on the organic mass loss rate due to photolysis and changes in this rate as a function of changes in the chemical composition and physical properties. This will increase understanding of aerosol atmospheric aging and lifetime and will reduce uncertainties due to aerosols in models.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2016-10-01
End Date
2017-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members