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Hugh Coe, James Allan, Jonathan Taylor, Michael Flynn, Paul Williams, Gavin McMeeking, Greg Kok, Darrel Baumgardner, Tim Onasch, Ed Fortner, John Jayne and Doug Worsnop
Ambient measurements of black carbon using the new SP-AMS in conjunction with other instruments
Ambient measurements of black carbon using the new SP-AMS in conjunction with other instruments
Image courtesy of SRTM Team NASA/JPL/NIMA
AGU FALL MEETING 2010: A14A-05, 13 December 1700
Cal Tech ground site (northern Los Angeles, CA).
15 May – 15 June 2010
Field deployment: Cal-NEx Los Angeles
Weekday/weekend and diel patterns3-9 June weekdays only
Entire campaign
Local morning traffic peak?
mean1 std deviation
Marr and Harley, ES&T, 2002 – CENTRAL VALLEY
light-duty
heavy-duty
Weekend effect has been observed in LA before: e.g., Turpin and Huntzicker (1991) ; Young et al. (1994)
Black carbon coatings II: 3-9 June
SP-AMS coatings normalized by absorption/SP2 rBC
for 150 nm BC core only!
0.6
0.4
0.2
0.0
Att
en
ua
tion
220°C2001801601401201008060Denuder Temperature (°C)
BC LV-OOA SV-OOA BBOA HOA SO4
NO3
Volatility
SP-AMS PMF analysis SP2 coating information
Conclusions• BC mass shows clear diel and
weekday/weekend patterns at Cal Tech site• Some evidence of diel pattern in BC coatings
linked to nitrate• No clear effect on Aethalometer absorption!• Volatility of coatings consistent with
expectations• SP-AMS capable of measuring BC mass and
coatings; quantification a major development target (calibration & focusing)
• Thanks to:– Cal Tech for hosting and CARB for infrastructure/logistics support!– Jochen Stutz (UCLA)– Joost DeGouw, Karl Froyd, Tim Bates, Shane Murphy (NOAA)– Jose Jimenez, Patrick Hayes, Amber Ortega (CU Boulder)– John Seinfeld, Puneet Singh (Caltech)– Paola Formenti (Aerodyne)– Jim Smith (NCAR)– Manuel Dall’Osto (IDAEA-CSIC)– Stefano Decesari (CNR Bologna)– The rest of the Calnex-LA team
MC4NE/H008136/1
Air from stack
SP-AMS
Thermaldenuder
Aethalometer
PM1 cyclone Drier
SP2PASS
Bypass
Automated Valve
Air from stack
SP-AMS
Thermaldenuder
Aethalometer
PM1 cyclone Drier
SP2PASS
Bypass
Automated Valve
200
150
100
50
0
SP
-AM
S io
n ra
te (
Hz)
1.21.00.80.60.40.20.0
SP2 mass (µg m-3
)
350
200
80
500250
125
225
Numbers denote mobility diameter in nm Coefficient values ± one standard deviation
a =-7.153 ± 21.2b =181.48 ± 28.1
• PIKA analysis needed
• V mode was sufficient to resolve carbon clusters
36.1536.1036.0536.0035.9535.9035.85
15
10
5
0
Diff
, Hz
15
10
5
0
Op
en, H
z/n
s15
10
5
0
Clo
sed,
Hz/
ns
1.00.0
-1.0
Res
id
HCl
H234
S
C3