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Data Analysis/Monitoring Session OAQPS Updates Neil Frank RPO National Workgroup Meeting Dallas TX December 3-4, 2002
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Topics Reconciliation of IMPROVE/STN data and 6 sites Study (5 minutes) Urban Excess and Elevation Adjustments (20 minutes) Status of Draft Guidance Documents (5 minutes) Access to Canadian Data (5 minutes) Discussion (10 minutes)
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IMPROVE/STN Intercomparisons
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The 6 Site Intercomparison Collocated sampling at 6 sites –12 months sampling completed Oct 20 02 –To continue most sites through July 03 One additional site operated by NYS Data will be compared for all “common” analytes –1 st year data analyses ready in March 2003
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Pinnacles St Park, NY R&P Sampler
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IMPROVE = 0.89STN - 0.00 R 2 = 0.88 New York PM-2.5 Species Data (April – Nov 01: STN vs. IMPROVE (provided by Dirk Felton, NYSDEC)
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What else will help us understand IMPROVE vs. STN? Inter-lab comparison of the same quartz filters –Carbon measurements associated with the different DRI and STN analytical procedures –Detailed analysis of data and the thermograms –With help from EPA/ORD, will look for Seasonal or site differences Potential effect of predominant emission sources ? Study of shipping procedures during spring/summer ’03 Study of blank filter corrections for STN –Current focus on carbon
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Urban Excess and Elevation Adjustments
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From: Latest Findings on National Air Quality, 2001 Status and Trends Ambient PM2.5 Composition in Rural Areas SO4 and associated NH4 are prevalent in Rural Eastern PM2.5 IMPROVE network, 1999
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From: Latest Findings on National Air Quality, 2001 Status and Trends Ambient PM 2.5 Composition in Urban Areas More Carbon and Nitrates in Urban Areas vs. Rural Areas EPA STN network, 2001
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What Data are Selected for Comparison of Urban STN and Rural IMPROVE Sites? Time Period: Mar 2001-Feb 2002 Air Quality: 12-month average concentrations Measurements to account for PM2.5 mass –Sulfates, Ammonium, Nitrates –Organic Carbon (OC), Elemental Carbon(EC) –Certain Elements: Al, Si Ca, Fe, Ti To estimate crustal component Required data completeness –For each calendar quarter 50% of observations (i.e. > 15)
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Data Handling Protocols How did we treat Ammonium (NH 4 + ) ? Although STN measures NH 4 at all sites, NH 4 + for STN and IMPROVE are estimated –from sulfate (SO 4 - ) & nitrate (NO 3 - ) concentrations, assuming Sulfates are ammonium sulfate, (NH 4 ) 2 SO 4 Nitrates are ammonium nitrate, NH 4 NO 3 For consistency with IMPROVE
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Data Handling Protocols How did we treat carbon? OC and EC data are not separately presented IMPROVE and STN use different thermo-optical techniques to measure carbon Total Carbonaceous Mass is estimated as TCM = k* OC +EC, Range of TCM is considered, with k= 1.4 and 1.8 OC is blank corrected –for STN using network-wide estimates –IMPROVE data is already corrected
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Preliminary OC Blank Correction for STN Derived from network average quartz filter field blanks Appropriate to adjust annual averages Varies by 24-hr sampler volume –MetOne (SASS): 9.6 m 3 –Anderson (RASS): 10.4 m 3 –R&P: 14.4 m 3 –URG (MASS): 24 m 3 –IMPROVE: 32.8 m 3 Avg OC blank, ug/m3
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PM2.5 Mass Concentration, ug/m3 OC concentration, ug/m3 Evaluation of STN OC blank correction for 12-month averages using measured OC vs PM2.5 mass
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Data Handling Protocols How did we estimate “crustal” component? Crustal (fine soil) = 2.2[Al]+2.49[Si]+1.63[Ca]+2.42[Fe]+1.94[Ti] –For consistency with IMPROVE
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What sites are considered? Selected Urban Sites –From EPA’s PM2.5 Speciation Trends’ Network (STN) –13 of 35 sites with complete data Selected Rural Sites –From IMPROVE Network (including protocol sites) 98 sites to describe spatial patterns 16 sites paired with the urban sites for urban-rural comparisons
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EPA Speciation Trends Network 35 complete sites initially selected for analysis 35 STN sites
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IMPROVE Network, 2002 98 Sites with “complete” data, Mar 01-Feb 02
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13 Selected Urban Sites are Paired with Rural Sites for “Urban PM2.5 Excess” Calculations Fresno Indy S.L. Tulsa Missoula SLC Bronx Charlotte Baltimore Atlanta Cleveland Richmond Birmingham 16 rural IMPROVE sites 13 urban STN sites
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Are the Rural IMPROVE Sites Indicative of Regional Background for Comparison to Urban Sites? Let’s look at Spatial Patterns for SO4, NO3 and Carbon
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Rural Sulfates: March 01 – Feb 02
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Rural Nitrates : March 01 – Feb 02 ??
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Rural Total Carbonaceous Mass: March 01 – Feb 02 TCM=1.8*OC+EC
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Now, lets estimate urban excess First in terms of gravimetric mass Then, specific species
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Urban PM2.5 is Higher than Nearby Rural Concentrations Top: Urban Bottom: Rural 12-month average PM2.5 mass with speciation samplers
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Dolly Sods, WV Rural IMPROVE site (background) Baltimore MD STN urban site Rural Concentrations Superimposed on Urban Rural Concentrations Adjusted for Elevation differential “Urban Excess” = Urban – Rural concentrations Estimated Annual “Urban Excess” for Baltimore, MD Top bars are urban concentrations Bottom bars are nearby rural concentration
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Elevation adjustment is a small technical correction to the “Urban Excess” calculation Urban excess after elevation adjustment Concentration, ug/m3 Estimated Annual “Urban Excess” for Baltimore, MD Concentration at 1158m (Dolly Sods) is 12% lower than sea level
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Focus on Dolly Sods, WV Average Sulfate March 01 – Feb 02 Elevation adjustment increases average DOSO sulfate to 4.8 ug/m3
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Examples of Other Urban-Rural Pairings
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Range of TCM based on “k”= 1.4 to 1.8 (k=1.4) Ambient Urban Excess Concentrations for 13 example areas “Urban Excess” = urban concentration – regional background 2.46.4 TCM (k=1.4): 10.5
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TCM (k=1.8) TCM (k=1.4) Crustal Concentration, ug/m3 PM2.5 Urban Excess is Mostly Carbon 12-month average PM2.5 mass and components with speciation samplers
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w. FRM mass w. STN mass Carbon Excess Percentage is even higher when FRM mass is used
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Status of Draft RH Guidance Documents
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Regional Haze Guidance Two guidance documents prepared to support States in preparing SIPs –Draft Guidance for Tracking Progress Under the Regional Haze Rule –Draft Guidance for Estimating Natural Conditions Under the Regional Haze Rule
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Chronology of the Guidance Review Distributed for public review in October, 2001 Notice of availability in Federal Register in December 2001 to spur additional comments Distributed for technical peer review in April, 2002 Responses in preparation by EPA/State/RPO/NPS working group (contract related delays) Revised Guidance expected January 2003
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Technical Peer Review Committee –Bruce Hill Clean Air Task Force –Rich Poirot Vermont Department of Environmental Conservation –Ivar Tombach Environmental Consultant –James Watson Desert Research Institute –Warren White Washington University
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Response to Comments some key points Technical peer review and public comment addressing scientific issues –Substantial rewriting of several sections and new technical appendices for clarification (not new science) –Refinements to substitution procedures -- Sensitivity analyses with new f(RH) Many editorial changes and clarifications -- Revised monthly avg f(RH)
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Access to Canadian Data
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North American Particulate Matter Database North American Atmospheric Chemistry (NAAtChem) Database is under development –Collaboration of National Atmospheric Chemistry (NAtChem) Database and Analysis Facility (operated by Environment Canada) and Clean Air Markets Division (EPA) with full web-based data access likely to be completed in about 6 to 12 months. In the meantime, data available by request Contacts: –Bob Vet (EC) –Gary Lear (CAMD/EPA)
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What data is in NATChem? NAtChem archives 3 types of data from regional scale networks in the USA and Canada: Precipitation Chemistry, Particulate Matter and Toxics data The NAtChem Particulate Matter Database consists of –a number of US and Canadian data sets
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How network differences are treated? The differences between the networks/data are documented. NatChem has converted all data to 0 deg C, 760 mm Hg except those data at ambient conditions. –Methods to further harmonize STP/LTP units underway
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