skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Optical Properties of Airborne Soil Organic Particles

Abstract

Recently, airborne soil organic particles (ASOP) were reported as a type of solid organic particles emitted after water droplets impacted wet soils. Chemical constituents of ASOP are macromolecules such as polysaccharides, tannins, and lignin (derived from degradation of plants and biological organisms). Optical properties of ASOP were inferred from the quantitative analysis of the electron energy-loss spectra acquired over individual particles in the transmission electron microscope. The optical constants of ASOP are further compared with those measured for laboratory generated particles composed of Suwanee River Fulvic Acid (SRFA) reference material, which was used as a laboratory surrogate of ASOP. The particle chemical compositions were analyzed using energy dispersive x-ray spectroscopy, electron energy-loss spectroscopy, and synchrotron-based scanning transmission x-ray microscopy with near edge x-ray absorption fine structure spectroscopy. ASOP and SRFA exhibit similar carbon composition, but SRFA has minor contributions of S and Na. When ASOP are heated to 350 °C their absorption increases as a result of their pyrolysis and partial volatilization of semi-volatile organic constituents. The retrieved refractive index (RI) at 532 nm of SRFA particles, ASOP, and heated ASOP were 1.22-62 0.07i, 1.29-0.07i, and 1.90-0.38i, respectively. Compared to RISRFA, RIASOP has a higher real part but similar imaginarymore » part. These measurements of ASOP optical constants suggest that they have properties characteristic of atmospheric brown carbon and therefore their potential effects on the radiative forcing of climate need to be assessed in atmospheric models.« less

Authors:
 [1];  [1];  [2];  [1];  [3]; ORCiD logo [4]
  1. William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
  2. Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States; Department of Chemistry, University of California, Berkeley, California 94720, United States
  3. Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
  4. Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084 United States
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
OSTI Identifier:
1406766
Report Number(s):
PNNL-SA-127009
Journal ID: ISSN 2472-3452; 49234; 49711; 49232; KP1704020
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: ACS Earth and Space Chemistry; Journal Volume: 1; Journal Issue: 8
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Environmental Molecular Sciences Laboratory

Citation Formats

Veghte, Daniel P., China, Swarup, Weis, Johannes, Kovarik, Libor, Gilles, Mary K., and Laskin, Alexander. Optical Properties of Airborne Soil Organic Particles. United States: N. p., 2017. Web. doi:10.1021/acsearthspacechem.7b00071.
Veghte, Daniel P., China, Swarup, Weis, Johannes, Kovarik, Libor, Gilles, Mary K., & Laskin, Alexander. Optical Properties of Airborne Soil Organic Particles. United States. doi:10.1021/acsearthspacechem.7b00071.
Veghte, Daniel P., China, Swarup, Weis, Johannes, Kovarik, Libor, Gilles, Mary K., and Laskin, Alexander. Wed . "Optical Properties of Airborne Soil Organic Particles". United States. doi:10.1021/acsearthspacechem.7b00071.
@article{osti_1406766,
title = {Optical Properties of Airborne Soil Organic Particles},
author = {Veghte, Daniel P. and China, Swarup and Weis, Johannes and Kovarik, Libor and Gilles, Mary K. and Laskin, Alexander},
abstractNote = {Recently, airborne soil organic particles (ASOP) were reported as a type of solid organic particles emitted after water droplets impacted wet soils. Chemical constituents of ASOP are macromolecules such as polysaccharides, tannins, and lignin (derived from degradation of plants and biological organisms). Optical properties of ASOP were inferred from the quantitative analysis of the electron energy-loss spectra acquired over individual particles in the transmission electron microscope. The optical constants of ASOP are further compared with those measured for laboratory generated particles composed of Suwanee River Fulvic Acid (SRFA) reference material, which was used as a laboratory surrogate of ASOP. The particle chemical compositions were analyzed using energy dispersive x-ray spectroscopy, electron energy-loss spectroscopy, and synchrotron-based scanning transmission x-ray microscopy with near edge x-ray absorption fine structure spectroscopy. ASOP and SRFA exhibit similar carbon composition, but SRFA has minor contributions of S and Na. When ASOP are heated to 350 °C their absorption increases as a result of their pyrolysis and partial volatilization of semi-volatile organic constituents. The retrieved refractive index (RI) at 532 nm of SRFA particles, ASOP, and heated ASOP were 1.22-62 0.07i, 1.29-0.07i, and 1.90-0.38i, respectively. Compared to RISRFA, RIASOP has a higher real part but similar imaginary part. These measurements of ASOP optical constants suggest that they have properties characteristic of atmospheric brown carbon and therefore their potential effects on the radiative forcing of climate need to be assessed in atmospheric models.},
doi = {10.1021/acsearthspacechem.7b00071},
journal = {ACS Earth and Space Chemistry},
number = 8,
volume = 1,
place = {United States},
year = {Wed Sep 27 00:00:00 EDT 2017},
month = {Wed Sep 27 00:00:00 EDT 2017}
}