Toward an Improved Understanding of Multiphase Reactions Occurring on Mineral and Soil Dust Aerosol Surfaces
EMSL Project ID
48892
Abstract
Aerosols derived from wind-blown soil represent a significant component of the global aerosol budget that has a large, but uncertain effect on Earth’s climate. These particles are comprised of minerals and organic matter whose reactivity toward atmospheric radicals and organic molecules can change the composition of dust particles and the way they interact with solar radiation. Atmospheric models used to predict air pollution and study climate change are unsuccessful at reproducing observed aerosol densities, size distributions, and composition in the atmosphere. This suggests that our present understanding of the fundamental mechanisms leading to secondary organic aerosol formation in the atmosphere is incomplete. Contributing to this uncertainty is a lack of information on how trace gases interact with soil dust. The objectives of this work are: (1) to characterize surface-catalyzed reactions of important secondary organic aerosol precursors on soil dust surfaces, and (2) study the multiphase chemistry of reactive nitrogen species with the naturally occurring organic constituents of soil dust. The objectives will be accomplished through reactivity studies using surface-sensitive analytical methods such as nanospray desorption electrospray ionization mass spectrometry, X-ray photoelectron spectroscopy, Raman microscopy, and high spatial resolution secondary ion mass spectrometry, that are uniquely available at EMSL. These methods will provide a molecular-level understanding of the role of soil dust surfaces in promoting heterogeneous and multiphase chemistry that was only previously thought to occur only in highly acidic media. The kinetic data and mechanistic insights gained will be implemented in state-of-the science chemical-transport models to fully evaluate the impact of the proposed chemistry on the fate of reactive nitrogen and aerosol growth and aging in the troposphere--processes that play a major role in air pollution and climate.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2015-10-01
End Date
2017-12-31
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
Hansen, R. F., Engelhard, M., and Raff, J., ?Toward an Improved Understanding of the Role of Soil Organic Matter in NOy Cycling through Investigation of Heterogeneous Reactions with NO2+.? Poster presentation (B13G-1827) at American Geophysical Union Fall Meeting 2017, New Orleans, LA, Dec. 11, 2017.
Hansen R.F., R.B. Abney, M.H. Engelhard, D.P. Veghte, S. China, and J.D. Raff. 12/12/2018. "Investigation of the Mechanism of the Reaction of Soil Organic Matter with N2O5." Presented by R.F. Hansen at AGU Fall 2018, Washington, District Of Columbia. PNNL-SA-140108.
Kebede M A,Bish D L,Lozovyi Y ,Engelhard M H,Raff J D 2016. "The Role of Iron-Bearing Minerals in NO2 to HONO Conversion on Soil Surfaces" Environmental Science & Technology 50(16):8649–8660. 10.1021/acs.est.6b01915