1. Using In-Network Precision Data as a Basis for Cross-Network Comparisons Warren H. White, Nicole P. Hyslop, and Charles E. McDade AAAR Specialty Conference: Particulate Matter, Supersites Program & Related Studies Atlanta, GA 11 February 2005

2. Module A (PM 2.5, Teflon Filter) Mesa Verde National Park, CO Proctor Maple Research Facility, VT Olympic National Park, WA Saint Marks National Wildlife Refuge, FL Sac and Fox Tribe, KS Trapper Creek (Denali National Park), AK Module B (PM 2.5, Nylon Filter) Big Bend National Park, TX Blue Mounds State Park, MN Frostburg Reservoir, MD Gates of the Mountains Wilderness, MT Lassen Volcanic National Park, CA Mammoth Cave National Park, KY Module C (PM 2.5, Quartz Filter) Everglades National Park, FL Hercules Glades Wilderness, MO Hoover Wilderness, CA Medicine Lake National Wildlife Refuge, MT Saguaro National Park (Western Section), AZ Seney National Wildlife Refuge, MI Module D (PM 10, Teflon Filter) Houston, TX (STN urban site) Jarbridge Wilderness, NV Joshua Tree National Park, CA Quabbin Reservoir, MA Swanquarter National Wildlife Refuge, NC Wind Cave National Park, SD collocated samplers in IMPROVE network starting summer 2003

3. collocated monitoring by Speciation Network uncertainty reporting started summer 2003 STN data provided by Shelly Eberly, EPA OAQPS

4. obligatory introductory slide When should both parties be happy with the results of a comparison? First impressions – how do the collocated and routine IMPROVE results compare? First impressions – how do the STN and IMPROVE results compare?

5. Se, ug/m 3

7. V, ug/m 3

9. Fe, ug/m 3

11. IMPROVE SO 4 = relative error arithmetic error

12. IMPROVE SO 4 = observed expected

13. cumulative distribution of observed / expected IMPROVE SO 4 =

14. unit normal distribution* * corresponding to normal error, unbiased with known precision IMPROVE SO 4 =

15. IMPROVE-IMPROVESTN-IMPROVE SO 4 =

16. STN - IMPROVE Are observed STN-IMPROVE differences accounted for by the two networks reported uncertainties? Yes! no!

17. How about collocated-routine differences within IMPROVE?

26. What I just said When should both parties be happy with the results of a comparison? When observed differences are consistent with reported uncertainties. First impressions – how do the collocated and routine IMPROVE results compare? We are generally happy, except with the crustal elements and S. First impressions – how do the STN and IMPROVE results compare? See C.E. McDade et al., this room, just 1 hour from now.