Continuous Carbon and NHy Measurements Eric S. Edgerton, ARA, Inc. EMEP PM Measurement and Modeling Workshop New Orleans, LA, USA 4/20-23/04 EMEP 042104

Outline Continuous Carbon Continuous NHy (NH3) R&P 5400 (SEARCH) Aethelometer (SEARCH) Sunset Labs Particulate Carbon Analyzer (Turner, Robinson) Continuous NHy (NH3) An idea for constraining secondary OC EMEP 042104

5400 Schematic EMEP 042104

5400 Principle of Operation Collect particles in metal impactor (0.12 µM Dp50) for 60 minutes, or longer Measure ambient CO2 in analytical loop Heat impactor in 1-4 temperature plateaus, volatilize carbon (final T 600-750C) Heat afterburner to 750C, complete combustion to CO2 Quantify ΔCO2 via NDIR (Li-Cor) Repeat (w/o collection step) for artifact (residual) correction Note: For a 1-hour sample, the system produces 19 ppm of CO2 per ug-C/m3 EMEP 042104

5400 Precision Jefferson Street – July 2001 TC (ug/m3) EMEP 042104

5400i TC vs. TOR TC Jefferson Street, GA - 2001 SEARCH 5400i tends to under predict in winter, but over predict in summer EMEP 042104

5400f TC vs. TOR TC Jefferson Street, GA – 2003/4 EMEP 042104

Aethelometer Operation Collect particles on quartz filter tape at controlled flow Monitor absorbance continuously with reference ands sensor beam Advance tape at pre-set time interval or preset absorbance Wavelength-specific conversion to BC (1-minute + time resolution) Nafion drier (SEARCH sites) Activated carbon monolith EMEP 042104

Comparison of AETH-BC and TOR-EC at Jefferson Street (Atlanta), GA We see a consistent relationship across SEARCH sites, with regression slopes between 0.5 and 0.7 EMEP 042104

Time Series of 1-minute AETH-BC Jefferson Street (Atlanta), GA (nafion drier and carbon monolith) Dislocations observed virtually always at virtually all SEARCH sites, noise is instrument specific EMEP 042104

Sunset Labs Carbon Analyzer slide courtesy of Jay Turner, STLU EMEP 042104

Sunset Labs Temperature Program slide courtesy of Jay Turner, STLU EMEP 042104

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Pittsburgh Air Quality Study: Carbonaceous Aerosol Samplers CMU Denuder Sunset in situ Denuder PM2.5 Sunset in-situ OC/EC Analyzer Teflon All Quartz filters analyzed using Sunset Instruments and NIOSH protocol Denuder PM2.5 Quartz CIF Denuder Dynamic Blank Sample PM2.5 Quartz CIF Schematic of different samplers. Definitions of OC & EC shown are the values used in subsequent slides. Rutgers & Carnegie Mellon OC = Sample (Q+CIF) – Dynamic Blank (Q+CIF) EC = Sample Q – Dynamic Blank Q Source: Allen Robinson, Carnegie Mellon University; Barb Turpin Rutgers University EMEP 042104

Comparison of Sunset Labs In Situ with Integrated Samples Excellent agreement except for EC. Note that good agreement with CMU denuder sampler indicates that negative artifact from a denuded in situ not a problem presumably because of short sampling time of in situ? Problems with EC due to refractory build up on in situ filter. This causes premature evolution of EC and biases in split. We changed in situ filter a lot (every few days) during Pittsburgh Supersite. Paper in preparation on this issue. Source: Allen Robinson, Carnegie Mellon University; Barb Turpin Rutgers University EMEP 042104

Emissions from Biomass Burning HMS Fire and Smoke Summary for 2345 10/21/03 Oak Grove http://www.firedetect.ssd.nesdis.noaa.gov/index.htm EMEP 042104

CO and NOy at Oak Grove – 10/21/03 EMEP 042104

Comparison of ERs with Literature Values FUEL NOy (as NO) SO2 PM2.5 TC BC Savannah/Grassland 60 5.4 83 57 3.1 Trop. Forest 15 5.5 88 64 6.4 non-Trop. Forest 28 9 121 78 5.2 Biofuels 27 3.5 92 51 7.6 Ag. Residues 4.3 42 36 7.5 This Study (Fires) 28+/-14 5.0 +/-2/7 195 +/- 54 63 +/- 14 10 +/- 6.1 This Study (Urban)# 147 +/-10 n.d. 33 +/- 8 9.6 +/- 2.1 Andreae and Merlet. Global Geochem Cyclec 15(4):955-966. 2001. (A&M) # Based on Jefferson Street, Atlanta, GA SEARCH data ER (g/kg CO) EMEP 042104

Continuous Measurements of NHy in SEARCH EMEP 042104

SEARCH NH3 and %NHy 4th Quarter 2003 rural- agricultural urban-industrial % NHy urban-res./ind. urban- residential urban- residential NH3 (ppb) % NHy rural- forested rural- forested suburban 0.32 +/- 0.12 0.49 +/- 0.22 2.54 +/- 2.27 EMEP 042104

Total Reduced Nitrogen (NHy) Diagram Hot Pt converts NHy to NO. Hot Mo converts NOy to NO, but is blind to NHy. SEARCH EMEP 042104

NO3/NH4 Diagram SEARCH

Continuous NH3 vs Denuder NH3 24 Hour Samples Gaseous NH3 is deduced by subtracting particulate NH4 from NHy SEARCH EMEP 042104

Hourly NH3 and particulate-NH4+ Yorkville, GA – November 2003 EMEP 042104

Continuous NH3 vs. Wind Direction Yorkville, GA – November 2003 EMEP 042104

1.8 km 2.3 km 4.5 km The Smoking Chicken EMEP 042104

Continuous NH4+ and NO3- vs Continuous NH4+ and NO3- vs. Wind Direction Yorkville, GA - November 2003 Wind Direction EMEP 042104

WS and WD Yorkville, GA 11/6-8/01 Transport from Atlanta Low Wind Speed EMEP 042104

Particulate NO3- and NH4+ Yorkville, 11/6-8/01 EMEP 042104

An Idea for Constraining Secondary OC Primary Secondary Modern OC OC Fossil OC EMEP 042104

Simplified OC Source Matrix Primary Secondary Total Modern Speciation/CMB S peciation , Models, D ifference 14C Fossil Difference Combination of CMB and C-14 data allows calculation of secondary OC by difference. EMEP 042104

OC Source Matrix Atlanta, GA – January Primary * Secondary Total # Modern 64 +/- 15 <5 61 +/ - 5 Fossil 36 39 * 2000 Data: Zheng et al., ES&T, 2002. # from 14Cdata EMEP 042104

OC Source Matrix Atlanta, GA – July 2001 Primary* Secondary Total # Modern <5 +/- 10 >50 59 +/ - 6 Fossil 40 * +/- 18 41 * Zheng et al. Source Apportionment of Fine Particles at Atlanta, GA, AAAR 2002 # from 14C data EMEP 042104

Summary For TC, R&P 5400f (with modifications) can reproduce filter-based measurements(+/- 15%), but maintenance (data capture) can be problematic. Log cell pressure. For BC, aethelometer provides reliable, high time resolution information, but AETH-BC = 0.6(+/- 0.1) TOR-TC. Dislocations and high resolution noise are annoyances that require further investigation. Log fast data. For OC, TC and possibly EC, early results from Sunset Labs analyzer are promising. Longer term experience necessary. Continuous carbon and NHy data provide valuable insights into sources, processes, etc.