Supplemental Material for
Phase State and Physical Properties of Ambient and Laboratory Generated Secondary
Organic Aerosol
Rachel E. O’Brien, 1, 2* Alexander Neu,1 Scott A. Epstein,3 Amanda C. MacMillan,3
Bingbing Wang,4 Steve T. Kelly,1 Sergey A. Nizkorodov,3 Alexander Laskin,4 Ryan C.
Moffet,2 Mary K. Gilles,1
Geophysical Research Letters, 2014
[1] Lawrence Berkeley National Laboratory, Berkeley, California, 94720-8198, USA
[2] Department of Chemistry, University of the Pacific, Stockton, CA 95211, USA
[3] Department of Chemistry, University of California, Irvine, CA 92697-2025, USA
[4] William R. Wiley Environmental and Molecular Sciences Laboratory, Pacific Northwest
National Laboratory, Richland, WA, 99352, USA
*Address correspondence to the following author
Email: resellon@lbl.gov
Introduction
The following figures, text, and tables are referred to as supplementary material in the main text.
The text file provides more detailed information on sample generation, data collection, and
analysis. Figures S1 and S2 are plots of the full data sets, figure S3 is SEM images of
representative particles, and figures S4 and S5 are plots used for the thickness calculations
mentioned in the main text and detailed in the supplemental text. Tables S1 and S2 provide the
fits for the raw data sets, table S3 provides additional information on the conditions for the
chamber experiments, and table S4 provides results from the organic to inorganic thickness
calculations.
1. text01.txt Additional information on how the laboratory samples were generated, data
collection and analysis, and how the organic to inorganic thicknesses were calculated.
2. ts01.txt (Table S1) Ambient sample collection information and fitting results for optical
density at 320 eV (OD320) and OD278 vs. area equivalent diameter with 95% confidence intervals.
2.1 Column “Campaign” name of the field campaign the data originates from
2.2 Column “Year” year of the corresponding field campaign
2.3 Column “Number of Particles” number of organic dominated particles identified and used to
calculate slopes for the paper
2.4 Column “ 320eV Slope” Slope of the best fit line for the average OD320 per particle as a
function of the area equivalent diameter of the impacted particle. The 95% confidence intervals
are given
2.5 Column “ 320eV Intercept” Intercept of the best fit line for the average OD320 per particle as
a function of the area equivalent diameter of the impacted particle. The 95% confidence
intervals are given
2.6 Column “ 278eV Slope” Slope of the best fit line for the average OD278 per particle as a
function of the area equivalent diameter of the impacted particle. The 95% confidence intervals
are given
2.7 Column “ 278eV Slope” Slope of the best fit line for the average OD278 per particle as a
function of the area equivalent diameter of the impacted particle. The 95% confidence intervals
are given
3. ts02.txt (Table S2) Laboratory sample collection information and fitting results for optical
density at 320 eV (OD320) and OD278 vs. area equivalent diameter with 95% confidence intervals.
3.1 Column “Sample” name of the laboratory sample the data originates from
3.2 Column “MOUDI stage” MOUDI stage used for the sample collection
3.3 Column “Number of Particles” number of organic dominated particles identified and used to
calculate slopes for the paper
3.4 Column “ 320eV Slope” Slope of the best fit line for the average OD320 per particle as a
function of the area equivalent diameter of the impacted particle. The 95% confidence intervals
are given
3.5 Column “ 320eV Intercept” Intercept of the best fit line for the average OD320 per particle as
a function of the area equivalent diameter of the impacted particle. The 95% confidence
intervals are given
3.6 Column “ 278eV Slope” Slope of the best fit line for the average OD278 per particle as a
function of the area equivalent diameter of the impacted particle. The 95% confidence intervals
are given
3.7 Column “ 278eV Slope” Slope of the best fit line for the average OD278 per particle as a
function of the area equivalent diameter of the impacted particle. The 95% confidence intervals
are given
4. ts03.txt (Table S3) Summary of experimental conditions for the chamber experiments
4.1 Column “Sample” name of the laboratory sample the data originates from
4.2 Column “[HC]” concentration (ppm) of precursor initially injected into the chamber
4.3 Column “Oxidant precursor” oxidant used in the experiment
4.4 Column “[NO ppb]” concentration (ppb) of NO immediately prior to sample collection
4.5 Column “[NOy ppb]” concentration (ppb) of NOy immediately prior to sample collection
4.6 Column “[O3 ppb]” concentration (ppb) of ozone immediately prior to sample collection
4.7 Column “[T (°C)]” temperature in the chamber immediately prior to sample collection
4.8 Column “[Concentraiton (g/m3)]” concentration of particles immediately prior to sample
collection
4.9 Column “[Average Size (nm)]” average diameter of particles immediately prior to sample
collection
5. ts04.txt (Table S4) Average calculated organic to inorganic thickness ratios for each field
campaign
5.1 Column “Campaign” name of the field campaign the data originates from
5.2 Column “In=S, metals, etc.” dorg/din (% of thickness that is inorganic) assuming the inorganic
fraction is composed of sulfur and other metals
5.3 Column “In=NaCl” dorg/din (% of thickness that is inorganic) assuming the inorganic fraction
is composed of sodium chloride
5.2 Column “In=(NH4)2SO4” dorg/din (% of thickness that is inorganic) assuming the inorganic
fraction is composed of ammonium sulfate
6. ts05.txt (Table S5) Area equivalent diameters and OD320 and OD278 values for all the
particles analyzed in the text. This is the underlying data for figure 2 in the main text and figures
S1 and S2 in the supplemental material. The data are separated by the campaign or the
laboratory sample which is noted above each column. For brevity, one example column set is
shown below, this pattern repeats for all the data sets.
6.1 Column “ size (microns)” area equivalent diameter of the impacted particle in microns
6.2 Column “TCA” total carbon absorption (average optical density at 320 eV minus average
optical density at 278 eV) for the particle
6.3 Column “OD320” average optical density at 320 eV for the particle
6.4 Column “OD278” average optical density at 278 eV for the particle
7. fs01.tif (Figure S1) Optical thickness of carbon (total carbon absorption = OD320-OD278) as a
function of size of impacted organic particles for each ambient data set. Solid lines are best fit
lines for each data set and dashed lines are ±95% confidence intervals. The thick fitted lines are
reproduced in Figure 2 of the main text, and the slopes, intercepts, and confidence intervals are
listed in Table 1.
8. fs02.tif (Figure S2) Optical thickness of carbon (total carbon absorption = OD320-OD278) as a
function of size of impacted organic particles for each laboratory data set. Solid lines are best fit
lines for each data set; the same lines are reproduced in Figure 2 of the main text. The slopes are
listed in Table 1.
9. fs03.pdf (Figure S3) SEM images collected at a tilt angle of 75°. The white size bars
correspond to 2 m. a) Limonene flow tube, b) Isoprene-h- NOx, c) Cares T1 site, 6/28/2010
8:57 am LDT, d) Cares T1 site, 6/28/2010 14:18 pm LDT.
10. fs04.tif (Figure S4) Calculated mass absorption coefficients as a function of O/C at a) 320 eV
and b) 278 eV for chemical formulas from organic molecules found in atmospheric aerosols.
11. fs05.tif (Figure S5) Linear absorption coefficients at (a) 278 eV and (b) 320 eV for elements
found in atmospheric aerosols [Henke et al., 1993].