IMPROVE/STN Comparison & Implications for Visibility and PM2.5 John Graham, NESCAUM MANE-VU/MARAMA Science Meeting January 27, 2004 Goal of presentation: Present some information on modeling visibility conditions and hopefully stimulate discussion about how this information should be applied in developing a workplan for the MANE-VU planning process.

Overview The networks Direct comparison IMPROVE STN Direct comparison Addison Pinnacle SP, NY April 2001-Feb 2003 Mass, Major Species, Elements MANE-VU Extrapolated Visibility Source Apportionment question for consideration Conclusions/Recommendations

Background Origin of the networks Ongoing EPA review of differences: Sample Collection: monitor types Handling, Shipping, and Storage (after collection) Chemical Analysis: extraction and methods Data Manipulation: Blanks and artifacts Measurements: Mass and Elements on Teflon Ions on Nylon Organic and Elemental Carbon on Quartz Differences: IMPROVE- elemental H, PM-10; STN-expanded elements, positive ions

Monitoring Sites with Data covering June 2001 - May 2002

Addison Pinnacle State Park STN R & P 2300 Monitor Sample Volume Elements (24 m3) Ions & Carbon (14.4 m3) IMPROVE Volume (32.7 m3)

Comparison of PM2.5 Mass

Comparison of PM2.5 Reconstructed Mass

Comparison of SO42- Mass

Comparison of NO3 Mass

Elemental Carbon (mg/m3) Seasonal OC/EC All Seasons IMPROVE STN Original STN Simple Blank Corr STN OCX2 Corr' STN OCX2 Corr Season Elemental Carbon (mg/m3) winter 0.32 0.27 0.37 0.63 spring 0.28 0.22 0.38 0.71 summer 0.45 0.23 0.64 1.37 fall 0.36 0.25 0.42 0.78 Organic Carbon (mg/m3) 1.02 1.93 0.91 0.51 0.94 2.05 1.03 0.83 0.50 1.80 3.48 2.46 1.98 1.25 1.18 2.21 1.19 0.98 0.61

Time Series of DTC

STN vs. IMPROVE OC/EC STN is an adaptation of NIOSH Method 5040 “Elemental Carbon (Diesel Particulate)- Chosen to reflect EPA’s concern for PM2.5 Carbon health effects in urban environments IMPROVE methods designed for visibility impairment Believed that STN establishes EC/OC split closer to “true” EC OCX2 defined as OC evolved between time analysis reaches 550 °C and the introduction of O2 OCIMPROVE = OCSTN - OCX2 ECIMPROVE = ECSTN + OCX2 Blank Correction Needed for STN; applied to both OCSTN and OCX2 Recent Change-No longer reporting OCX2, instead multiple fractions as IMPROVE, although peaks remain unresolved

Comparison of Thermograms Temperature Ramp differences Reflectance (IMPROVE) vs. Transmittance (STN) IMPROVE 8 fractions vs. STN 2 Figures from JAWMA, Watson 2002

Blank Subtraction for C Trip and Field Blanks EC often > measured mass Analysis by Schwab (SUNY) of NYS STN Other monitor types C blanks ~93% OC Consistent with IMPROVE results R&P2300 interference from silicon grease; loading level affect on OC/EC split time No apparent seasonality OC blank 1.02 mg/m3 at Pinnacle SP EC blank 0.08 mg/m3 at Pinnacle SP Note for VIEWs users: reported STN values may have ½ MDL instead of ND, OC corrected for blank

Scatterplots of OC and EC TC = EC + OC’ + OCX2; OC’ and OCX2 are blank corrected proportionally OCX2 is split between OC/EC to mimic IMPROVE OC/EC Green is Original STN split; Blue is EPA’s initial recommendation; Red-MANE-VU OC, EC and OCX2 are reported for measurements until 7/2003 [OC = OC’ + OCX2]

Organic Carbon Timeseries

Elemental Carbon Timeseries

Timeseries for Select Elements

Combination of STN & IMPROVE for Visibility Interpolation based on available monitors and 1-year of data Seasonal figures are more spatially complete Extinction due to Carbon is a best guess estimate for STN, calculated as usual for IMPROVE Maps generated for each network separately resemble those for combination maps Units in Mm-1; Rough estimate of mass discernable

Fine Particle Extinction SPRING SUMMER FALL WINTER (Mm-1)

Sulfate Extinction SPRING SUMMER FALL WINTER (Mm-1)

Nitrate Extinction SPRING SUMMER FALL WINTER (Mm-1) (Mm-1)

Organic Carbon Extinction SPRING SUMMER FALL WINTER (Mm-1)

Elemental Carbon Extinction SPRING SUMMER FALL WINTER (Mm-1)

Source Apportionment Major Ionic Species and mass correlate well Many elemental species also well-correlated Some elements not well-correlated Questions: To what extent will poorly correlated minor species influence differences in source profile from SA models? Will inter-network OC/EC differences continue, or to what extent can changes in reporting STN fractions increase comparability?

Closing Remarks Substantial differences exist between networks Source Apportionment models should be applied to EPA’s collocated datasets to assess how these differences may affect source profile characterization Mass and major ions correlate well, useful in east due to dominance of Sulfate in visibility extinction from fine particles In depth analysis required to assess data comparability for use in assessing exposure to metals and EC