Aethalometer™ Work Update

1. Aethalometer™ Work Update Traffic Analysis Wood Smoke Sites Univ of Washington Diesel Exposure Lab

2. Objectives • To introduce our network and project objectives • To communicate analysis that has been accomplished by PSCAA • Traffic Analysis • Wood Smoke Sites • Univ of Washington Diesel Exposure Lab • To encourage other agencies to try continuous Black Carbon Technologies • To acknowledge Aethalometer™ strengths and weaknesses to further understand instrument capabilities

3. Aethalometer • Magee Scientific Dual Channel Aethalometer™ • BC Channel 880 nm • UV Channel 370 nm • Dr. Tony Hansen is the Principal Scientist • PM 2.5 Head at 5 LPM

4. Network “Big Picture” Network Scope 110 Miles • “Almost Pure” Wood Smoke Darrington Site • Sep 2004 • Marysville Wood Smoke North Site • Jan 2005 • Lake Forest Park Wood Smoke North Site • Dec 2003 • Freeway Site • Jan 2003 • Industrial Site • Oct 2002 • Urban Background Site • Jan 2003 • Wood Smoke South Site • Dec 2003 Blue Sites denote Speciation Network

5. Monitoring Strategy • Olive Street Freeway Site • 225,000 vehicles per day • Mostly Light Duty Vehicles • Seattle Duwamish Industrial Site • 58,000 vehicles per day • Port of Seattle – Truck Arterial • Seattle Beacon Hill Urban Background Site • 30,000 vehicles per day • Neighborhood Light Duty Vehicles

6. Site Comparison – Traffic Indications

7. Site Comparison – Traffic Indications

8. Site Comparison – Traffic Indications

9. Traffic Data Introduction • Traffic Data collected by WA DOT on Interstate 5 near our Freeway (Olive Street Aethalometer) site • Hourly Traffic Counts using a standard separation between Light Duty Vehicles and Heavy Duty Trucks • We compared this data to our Aethalometer BC data for a period of 2 weeks during a July Stagnation Period

11. Incorporating Speciation Data

12. Site Comparisons Using Speciation Data

13. Indicators • BC ≠ EC ≠ DPM • Harvard Research showed that the Aeth BC measurement is “directly related and equivalent to the filter based EC measurement.” • Thumbrule: 1.4(EC) = BC measurement. • UV ≠ OC ≠ WoodSmoke PM

14. Looking at the UV Channel • From Dr. Tony Hansen’s Operator’s Manual and from George Allen’s Research at NESCAUM: • UV – BC = “Delta” or “DC” • “UVPM” is Qualitative, but not Quantitative. • Absorption Cross Section of compounds that absorb light in the “UV” channel (370 nm) is highly variable. So this parameter “DC” has no physical engineering units. • In the following case, we will look at 2 sites: • 1 Site where we don’t expect to find a “WoodSmoke” indication • 1 Site where we DO expect to find a “WoodSmoke” indication

15. UV Channel Observations

16. DC (UV-BC) Statistics : Time Resolved

17. DC - 30 Day Running Average WoodSmoke Season

18. DC – 30 Day Running Average

19. Two Ways to look at UV Channel • DC Parameter – Defined as UV – BC. • A Positive Number represents a situation when Wood Smoke is Present • Using a regression of the data gathered in the Aethalometer, with the UV on the Y axis, and BC on the X axis, you get the slope of the curve. Defined as UV/BC. • Numbers Greater than 1 represent Wood Smoke is present. • Numbers Less than 1 represent when Diesel is present.

20. South Tacoma – Urban WoodSmoke

21. Darrington – Rural WoodSmoke

22. Duwamish – Industrial/Arterial

23. Univ Washington Diesel Exposure Lab

24. Summary Slide • Dual Channel Aethalometer • Monitoring Strategy • Temporal Patterns and Traffic Data • Temporal Patterns and WoodSmoke Data • Comparisons to Speciation Data • DC Parameter • Using the Slope of the BC/UV correlation curve • Acknowledgements: • Dr. Tony Hansen, George Allen, WA DOE NW, Heidi Curtiss, Darrington High School, Univ. Washington Diesel Exposure Lab