Supplementary material to “Chemical Characterization of Individual Particles and
Residuals of Cloud Droplets and Ice Crystals Collected Onboard Research Aircraft in the
ISDAC 2008 Study”
May 1, 2013
N. Hiranuma1, 6, S. D. Brooks1,*, R. C. Moffet2, 7, A. Glen1, A. Laskin3, M. K. Gilles2,
P. Liu4, A. M. Macdonald4, J. W. Strapp4, and G. M. McFarquhar5
1
Department of Atmospheric Sciences, Texas A&M University, College Station, Texas, 77843
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California,
94720-8226
3
W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National
Laboratory, Richland, Washington, 99352
4
Science and Technology Branch, Environment Canada, Toronto, Ontario, M3H 5T4, Canada
5
Department of Atmospheric Sciences, University of Illinois, Urbana, IL, 61801
6
now at Institute for Meteorology and Climate Research – Atmospheric Aerosol Research,
Karlsruhe Institute of Technology, Karlsruhe, Germany
7
now at Department of Chemistry, University of the Pacific, Stockton, California, USA
2
*Corresponding Author. E-mail: sbrooks@tamu.edu
Citation:
Hiranuma, N., S. D. Brooks, R. C. Moffet, A. Glen, A. Laskin, M. K. Gilles, P. Liu, A.M.
Macdonald, J. W. Strapp, and G. M. McFarquhar. Chemical Characterization of Individual
Particles and Residuals of Cloud Droplets and Ice Crystals Collected Onboard Research
Aircraft in the ISDAC 2008 Study, for Journal of Geophysical Research-Atmospheres
1
Introduction
This supplementary information provides additional details including STXM, identification of
cloud phase, location of the Con 580 aircraft during collection of each TRAC sample, and a
summary of the functional groups and peak areas of each functional group observed in single
particle carbon K-edge spectrum.
Measurement Details: Scanning Transmission X-ray Microscopy/Near Edge X-ray
Absorption Fine Structure Spectroscopy
Spectromicroscopic analysis of individual particles was performed on a subset of the
selected samples using the STXM instrument at the Advanced Light Source (ALS) of the
Lawrence Berkeley National Laboratory (Berkeley, CA). The STXM instrument has been
described here. For additional details see Kilcoyne et al., 2003 and Moffet et al., 2010a.
The sample is raster scanned in the focal plane of a focused beam of monochromatic Xrays (35 nm in diameter). After an image of the sample area is obtained, the energy is changed,
and the sample is scanned again. This process is repeated to obtain a set of energy resolved
spectral images. The range of X-ray energies covers the absorption due to excitation of a carbon
K-shell electron. Carbon K-edge features between 278 and 320 eV arise from electronic
transitions of K-shell electrons to unfilled molecular orbitals [Henke et al., 1993; Moffet et al.,
2010a]. At the lowest energies, characteristic electronic transitions occur from the 1s orbital (Kedge) to antibonding orbitals of the lowest unoccupied molecular orbital (LUMO π*). At slightly
higher energies, ionization or excitation to σ* orbitals can occur [Solomon et al., 2005].
2
Cloud Phase
Cloud phases are summarized in Table S1. Phases were identified based on the combined
data obtained by a number of in-situ particulate and cloud probes. The time resolution of the
TRAC sampling was 5 minutes. The Convair 580 traveled a great distance, typically >15 miles
in 5 minutes. Since the time resolution of particulate and cloud probes is higher, it was possible
to assign a cloud phase for each every 30 second interval of flight [McFarquhar et al., 2007].
The percentage of sampling time in cloud (mixed phase, liquid phase, or ice phase) or clear air is
summarized in Table S1. Mixed phase clouds are sometimes patchy, indicated by periods of
clear air within the 5 minutes during which the TRAC sample collected samples. Thus, the
distribution of liquid droplets and ice crystals may vary, even within a single cloud.
Table S1. Percentage of cloud phase during sampling onto substrates used in CCSEM/EDX and
STXM/NEXAFS analyses.
Particle Population
Sample ID
Cloud Phase, %
Biomass Burning
Cloud-Free Ambient
In-Cloud Residual
In-Cloud Residual
High IN (Residuals)
High IN (Residuals)
F25-S20
F30-S6
F30-S19
F31-S62
F34-S66
F34-S67
Clear
sky
100
100
0
0
70
40
Ice
Cloud
0
0
0
0
0
0
Mix
Phase
0
0
83
80
30
60
Liquid
Phase
0
0
17
20
0
0
3
Sample Collection Locations
For specific flights, backward trajectory calculations were performed using the HYSPLIT model [Draxler and Rolph, 2003].
Time averaged latitude, longitude, and altitude for each flight is summarized in Table S2. As shown in Manuscript Figure 4,
backward trajectories calculated for 5 days prior to aircraft collection showed sources and transport history of the particles, which
serve as potential CCN and IN.
Table S2. Average flight location (± standard deviation) for each sample collection period.
Particle Population
Sample ID
A. In-Cloud Residual
B. In-Cloud Residual
C. Cloud-Free Ambient
D. High IN (Residuals)
E. Biomass Burning
F30-S19
F31-S62
F30-S6
F34-S66-67
F25-S20
Latitude
71.2
72.4
70.6
71.2
71.4
±
±
±
±
±
0.04
0.04
0.04
0.05
0.08
Longitude
-151.4
-155.2
-150.9
-156.7
-155.6
±
±
±
±
±
0.21
0.28
0.16
0.19
0.14
Average
Altitude, m
577 ± 178
683 ± 157
5778 ± 405
955 ± 364
3011 ± 874
Highest, m
Lowest, m
765
835
6130
1509
4112
277
469
5176
430
1786
4
NEXAFS Function Groups and Peak Areas
The organic functional groups observed in a representative particle and the average peak
area derived from the single particle NEXAFS spectra (Manuscript Figure 3) are summarized
in Table S3. The spectrum of the particle contained significant contributions at 288.5 eV and
290.4 eV. The peak at 288.5 eV is the characteristic absorption of the carbon 1s  π*R(C*=O)OH
transition in carboxylic acid groups. The peak at 290.4 eV signifies the K 1s  π*C*O3 transition
in carbonates. Potassium peaks at 297.1 and 299.7 eV were also present. The particle contained
sp2 hybridized carbon-carbon double bonds identified as the peak at 285.4 eV.
5
Table S3. Summary of functional groups and peak areas of each functional group observed in the single particle carbon Kedge spectrum shown in Figure 3.
Peak Area (Optical
a
Energy, eV
Transition
Functionality
Depth x eV)
285.4
1s → π*
C*=C
0.17
286.5
K 1s → π*
R(C*=O)R or C*OH
0.15
287.7
K 1s → C-H*
C*H, C*H2, C*H3
0.46
288.5
K 1s → π*
R(C*=O)OH
0.82
289.5
K 1s → 3pσ*
R-OC*H2-R
0.60
290.4
K 1s → π*
C*O3
0.17
297.1 & 299.7
L2 2p1/2→ & L3 2p3/2→
Potassium
0.04
292.2
K 1s → σ*
C*-C, C*-O
1.06
300
1s → σ*
C*=C, C*=O
1.55
†
Edge step
Total Carbon
12.74
a
Excited state transition. Chemical bonding information are referred from Moffet et al. (2010), and references therein.
This is the area from the step function peaked at 294.5 eV that includes the energy to 320 eV. This area is related to the total
carbon present within the sample.
†
6
References
Draxler, R. R. and G.D. Rolph. (2003), HYSPLIT (Hybrid Single-Particle Lagrangian Integrated
Trajectory) model, Air Resource Laboratory, NOAA, Silver Spring, Md. (Available at
http://www.arl.noaa.gov/ready/hysplit4.html).
McFarquhar, G.M., G. Zhang, M.R. Poellot, G.L. Kok, R. McCoy, T. Tooman, A. Fridlind, and
A.J. Heymsfield. (2007), Ice properties of single-layer stratocumulus during the Mixed-Phase
Arctic Cloud Experiment: 1. Observations. Journal of Geophysical Research-Atmospheres, 112,
D24201.
Moffet, R.C., T. Henn, A. Laskin, and M.K. Gilles. (2010a), Automated Chemical Analysis of
Internally Mixed Aerosol Particles Using X-ray Spectromicroscopy at the Carbon K-Edge,
Analytical Chemistry, 82, 7906-7914.
Moffet, R.C., A. Tivanski, and M.K. Gilles. (2010b) Scanning Transmission X-ray Microscopy,
in Fundamentals and Applications in Aerosol Spectroscopy, edited by R. Signorell and J.P. Reid,
pp. 419-462, CRC Press, Boca Raton, FL.
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