1. Chemical Composition of PM2.5 over N. America Big Bend (scale 0-15 ug/m3) G.Smoky Mtn. Yellowstone Mammuth Cave Sequoia ? ?

2. Aerosol Types Aerosol are composed of multiple types. Each type may be considered a different pollutant since it has its own class of sources, aerosol properties and is associated with different effects. In other words, sulfate, nitrate organics, dust (soil) components of PM have no more commonalities then CO, NOx and SO2. The aerosol types are lumped into “PM2.5” by the current regulations. The IMPROVE aerosol types are:IMPROVE aerosol types SULFATE = 4.125*S Ammonium sulfate NITRATE = 1.29*NO3Ammonium nitrate ORGANICS = 1.4(O1+O2+O3+O4+OP)1.4* various organics (OMC) SOOT = E1+E2+E3+OPLight absorbing carbon (LAC) SOIL = 2.2AL++2.49SI+1.63CA+2.42FE+1.94TI Crustal elements FMASS = SULFATE + NITRATE + LAC + OCM + SOILReconstructed fine mass CMASS= MT-MF Coarse=PM10-FMASS Issue: Each aerosol type has many variants in nature. I think that the IMPROVE typing (aggregation) used by Malm & Co is good and it should be retained for presenting the network results. Need for alternative aggregations? I am open for discussion RBH.

3. Method: Cumulative Seasonal PM2.5 Composition PM2.5 chemical components were calculated based on the CIRA methodologyCIRA methodology In addition, the the organics were (tentatively) further separated as Primary Smoke Organics (red) and Remainder organics (purple) PSO = 20*(K - 0.15*Si – 0.02* Na) Remainder Org = Organics - PSO Also, the ‘Unknown’ mass (white area) is the difference between the gravimetrically measured and the chemically reconstructed PM2.5. The daily chemical composition was aggregated over the available IMPROVE data range (1988-99) to retain the seasonal structure. I order to reduce the noise the daily data were smoothed by a 15-day moving average filter. Shenandoah

4. Regional Grouping of Sites IMPROVE sites were grouped as follows: –New England () –Mid-Atlantic () –Central EUS () –Peripheral ()

5. Peripheral Sites: Chemical Mass Balance Eastern N. America is surrounded by aerosol source regions such as Sahara and Central America. As a consequence, the PM concentration at the ‘edges’ ranges between 4-15 ug/m3; much of it originating outside. The chemical composition of the inflow varies by location and season. Sahara dust, and smoke from Central America and W. US/Canada are the main contributions. Badlands (scale 0-15 ug/m3) Big Bend (scale 0-15 ug/m3) Voyageurs (scale 0-15 ug/m3) Acadia Everglades

6. Peripheral Sites Badlands (scale 0-15 ug/m3) Big Bend (scale 0-15 ug/m3) Voyageurs (scale 0-15 ug/m3) Acadia Everglades

7. Upper BuffaloMammuth CaveShining Rock G.Smoky Mtn. Sipsy

8. Mid-Atlantic Region Shenandoah Washington DCBrigantine Dolly SodsJefferson

9. New England Region Lye Brook MoosehornAcadia Proctor Maple Ringwood

10. Upper Midwest Badlands Voyageurs

11. TX, NM Chiricahua Bandelier White RiverGuadalupe Big Bend

12. TX, NM Tonto Petrified For.Saguaro Chiricahua

13. TX, NM Tonto Petrified For.Saguaro Chiricahua

14. Idaho Tonto Three SistersYellowstone Bridger Jawbridge Great Basin

15. California - Background Bliss State (2043 m) Lessen (1800 m) Crater Lake (1980 m) Point Reyes (38 m, Beach)

16. California - Perturbed Yosemite S. Lake TahoeSequoia San Gorgonio Pinnacles

17. Northwest - Perturbed Abbotsford (0 m) Chilliwack (9 m) Puget Sound (99 m) Columbia River (90 m) Mt. Rainier (436 m)

18. Remote ‘Global’ Sites Denali (640 m) Virgin Islands (46 m) Mauna Loa (3398 m)

19. Chemical Speciation of the Fine Mass Based on IMPROVEIMPROVE See Sisler & MalmSisler & Malm Over the remote Eastern US, sulfates dominate the Fine Mass The Southeast is also influenced by ‘smoke’ (organics+LAC) and dust. Over the West, organics, nitrates and dust dominate