1. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Analysis of Atmospheric Mercury Speciation at HEDO Station, Okinawa

2. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Shanghai Hong Kong Beijing

3. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com)

4. Anthropogenic Sources of Hg in 1995 Pacyna et al.- 2003 LRT Workshop Hg 0 – Ton/yr Hg(II) – Ton/yr PHg – Ton/yr

5. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Atmospheric Mercury Nomenclature Hg 0 or GEM - Gaseous Elemental Mercury PHg – Particulate Bound Hg (2.5 um) RGM - Reactive Gaseous Mercury - HgCl 2 ?

6. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Instrument Description: Atmospheric Mercury Speciation

7. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com)

8. Measurement vs Model Hedo Mean Hg 0 = 2.04 ng/m 3 Hedo Max Hg 0 = 5.47 ng/m 3 Seignuer et al., 2004 ES&T 38:555

9. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Measurement vs Model Dastoor and Larocque., 2004 Atmos. Env. 38:147 Hedo Mean Hg 0 = 2.04 ng/m 3 Hedo Max Hg 0 = 5.47 ng/m 3

10. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Measurement vs Model Hedo RGM Mean = 4.51 pg/m 3 Hedo RGM Max = 32.5 pg/ m 3 Seignuer et al., 2004 ES&T 38:555

11. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Measurement vs Model Hedo PHg Mean = 3.05 pg/m 3 Hedo PHg Max = 16.5 pg/ m 3 Seignuer et al., 2004 ES&T 38:555

12. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Comparison of Model and Observation of Hg 0 Seignuer et al., 2004 ES&T 38:555 LocationDateModel (ng/m 3 ) Obs W. KoreaSpring 2001 3.722.13 Seoul, KoreaSept-97 May-98 3.43-3.942.03; 2.12 Kyushu, Japan199610.81.70 Beijing, ChinaJan, Feb, Sept 98 6.2 – 24.72.26; 2.38 HEDO, OkinawaSpr-20041.7-1.92.04 Changchun, China **PHg** Jul-Jan 2000 0.02-2 (PHg)0.06 - 2

13. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Beijing - China

14. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com)

20. LOCAL?

21. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com)

27. High Hg 0 and CO often begins with rainfall note also SO 4 washout

28. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Evidence for Biomass Signal? Organic Rich – Sulfate Low

29. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Evidence for Biomass Signal? Organic Rich – Sulfate Low

30. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) NAAPS Forecast Smoke SO4

31. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) No clear observation of a dust event

32. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) NAAPS Forecast – over predicts Dust SO4

33. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com)

35. Low-Level RGM and PHg Emissions results in faster local removal by Dry Deposition? < 50 Meter Total Hg Emissions (tons/yr) >150 Meter Total Hg Emissions (tons/yr) Pacyna et al.- 2003 LRT Workshop

36. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Why are RGM values lower than models and uncorrelated with pollution compounds? Hypothesis – RGM from anthropogenic emissions are preferentially reduced to Hg 0 via the complex chemistry of S0 2 > S0 3 > S0 4 during cloud droplet formation and evaporation

37. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) What controls [RGM] – Photochemistry?

38. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Hg 0

39. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Future Data Interpretation More refined analysis of each event with respect to AMS and meteorology Support hypothesis that SO3 is preferentially converting emitted Hg(II) to Hg 0 during cloud water processing (formation/evaporation) Rule out local impacts

40. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Future: Need Hg Deposition Data! Inventories coupled to models predict high deposition in NW Pacific due to RGM and PHg emissions Measurements needed to confirm at HEDO and elsewhere Should be event based – at least for intensive study periods What Hg deposition data is currently being collected or published?

41. Eric Prestbo Ph.D. (ericp@frontiergeosciences.com) Continuous Mercury Speciation at HEDO Depending on support-level we can do complete Automated Hg speciation system – or only total gaseous Hg with select intensive studies