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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

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The Soot Particle-AMS

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BC and absorption instrumentation

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Cal Tech ground site(northern Los Angeles, CA).

15 May 15 June 2010

Field deployment: Cal-NEx Los Angeles

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Black carbon mass

spurious SP-AMS signal?

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Weekday/weekend and diel patterns3-9 June weekdays only

Entire campaign

Local morning traffic peak?

mean

1 std deviation

Marr and Harley, ES&T, 2002CENTRAL VALLEY

light-duty

heavy-duty

Weekend effect has been observed in LA

before: e.g., Turpin and Huntzicker(1991) ;Young et al. (1994)

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Black carbon coatings: 3-9 June

early morning pattern in mixing state/coating

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Black carbon coatings II: 3-9 June

SP-AMS coatings normalized by

absorption/SP2 rBC

for 150 nm BC core only!

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SP-AMS focusing and BC size?

No change in Aeth response

How do we

interpret

coating

information?

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0.6

0.4

0.2

0.0

Attenuation

220C2001801601401201008060

Denuder Temperature (C)

BCLV-OOASV-OOABBOAHOASO4NO3

Volatility

SP-AMS PMF analysis SP2 coating information

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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)

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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 DallOsto (IDAEA-CSIC)

Stefano Decesari (CNR Bologna)

The rest of the Calnex-LA team

MC4

NE/H008136/1

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Air from stack

SP-AMS

Thermal

denuder

Aethalometer

PM1 cyclone Drier

SP2PASS

Bypass

Automated Valve

Air from stack

SP-AMS

Thermal

denuder

Aethalometer

PM1 cyclone Drier

SP2PASS

Bypass

Automated Valve

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200

150

100

50

0

SP-AMSionrate(Hz)

1.21.00.80.60.40.20.0

SP2 mass (g m

-3

)

350

200

80

500

250

125

225

Numbers denote mobility diameter in nmCoefficient values one standard deviation

a =-7.153 21.2b =181.48 28.1

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PIKA analysis

needed

V mode wassufficient to

resolve carbon

clusters

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