Atmospheric Mercury and the Great Lakes

1. Atmospheric Mercury and the Great Lakes Richard Artz Deputy Director 301-713-0972 bruce.hicks@noaa.gov Mark Cohen Physical Scientist 301-713-0295 x122 mark.cohen@noaa.gov NOAA Air Resources Laboratory, 1315 East West Highway, R/ARL, Room 3316, Silver Spring, Maryland, 20910 http://www.arl.noaa.gov http://www.arl.noaa.gov/ss/transport/cohen.html Background materials prepared for a meeting with Cholly Smith, Staff of Rep. Mark Kirk (R-IL), 2:00 pm, Monday, April 18, 2005, Room 1717, Longworth House Office Bldg

2. Large programs are studying the magnitude and consequences of aquatic mercury pollution  At the NOAA Air Resources Laboratory, we are interested in where the mercury comes from. The source is primarily atmospheric deposition of mercury emitted to the air from coal combustion and other anthropogenic sources. We model the emissions, dispersion, and deposition of mercury from all sources, and identify those sources that contribute most to specific receptors. We measure mercury in the atmosphere directly, to verify model predictions.

4. Overall Modeling Methodology • Start with atmospheric mercury emissions inventory • Perform atmospheric fate and transport modeling of these emissions • Keep track of source-receptor information during the modeling for key receptors, including the Great Lakes, Chesapeake Bay, Lake Champlain, and others • Evaluate the modeling by comparison of the predictions against ambient monitoring data • If model is performing satisfactorily, report source-receptor results from the simulations • Similar to earlier work with other pollutants (e.g., dioxin & atrazine)

5. Sources of atmospheric mercury to Lake Michigan U.S. and Canadian mercury emissions Top 25 sources of atmospheric mercury to Lake Michigan Emissions and deposition to Lake Michigan arising from different distances

6. Additional Background Information

7. NOAA Air Resources Laboratory

8. Air Resources Laboratory Headquarters Silver Spring, Maryland Director B. B. Hicks Deputy R. S. Artz Surface Radiation Research Branch Boulder, CO J. J. Michalsky Transport Modeling & Assessment Climate Variability & Trends Air Surface Exchange & Chemistry Radiation and Aerosols 19 Federal employees 4 Contractors Exec. Assistant: Betty Wells Administration: Sharon Hamilton 4 Federal employees 11 CIRES 3 Others Secretary: Gwen Andersen Atmospheric Turbulence and Diffusion Division Oak Ridge, TN Director R. P. Hosker Deputy T. P. Meyers Atmospheric Sciences Modeling Division Research Triangle Park, NC Director S. T. Rao Deputy W. B. Petersen Field Research Division Idaho Falls, ID Director K. L. Clawson Deputy T. B. Watson Special Operations and Research Division Las Vegas, NV Director D. Randerson Deputy D. A. Soule Dispersion Studies Air-Surface Interactions Measurement Technologies Aircraft Operations 12 (+1) NOAA employees 23 Contractors (ORAU) 6 Others Secretary: Sharon Conger Administration: Barbara Shifflett Atmospheric Model Development Air-Surface Processes Modeling Model Evaluation and Applications Air Policy Support 50 NOAA employees 4 Contractors 23 Others Secretary: Patricia McGhee Administration: Herb Viebrock Dispersion Analyses and Modeling INEEL Meteorology & Dispersion Atmospheric Tracers 10 NOAA employees 3 Contractors Secretary: Joyce Silvester Administration: Paulette Fee Dispersion Studies NTS Meteorology and Dispersion Technical Services 17 NOAA employees 3 Contractors CIASTA (JI) Secretary: Boots Parker Administration: Barbara Pierce

10. Hg Hg Hg • Headquarters Division -- HQ (Silver Spring, MD)development of improved transport and dispersion models; • making ARL products operational through direct interaction with NCEP. • Atmospheric Sciences Modeling Division – ASMD (Research Triangle Park, NC) • development of improved air quality models, for both assessment and forecasting, • through direct interaction with the EPA and other federal partners. • Atmospheric Turbulence and Diffusion Division – ATDD (Oak Ridge, TN) improving descriptions of atmospheric dispersion and deposition in models, • emphasizing complex situations, and on developing improved instrumentation. • Field Research Division – FRD (Idaho Falls, ID) field atmospheric tracer testing facility, for developing transport and diffusion models; FRD’s mesonet and modeling expertise supports the Idaho National Laboratory. • Special Operations and Research Division – SORD (Las Vegas, NV) models atmospheric transport, dispersion, and deposition over complex terrain; • studies the effects of airborne particles on atmospheric radiation and opacity; • and provides dispersion guidance to DOE managers of the Nevada Test Site. • Surface Radiation Research Branch – SRRB (Boulder, CO) provides basic data on radiation fields, for the next generation of atmospheric transport • and dispersion models, by climate assessments, and by evaluations of climate models.

12. ARL Mercury Research Atmospheric measurements • process understanding, • study spatial/temporal trends - develop & evaluate models • ground-level speciated air concentrations • upper-air speciated air conc. using aircraft • wet and dry deposition • surface exchange Atmospheric modeling • to interpret measurements, • to get source-receptor data, • to predict future impacts • back-trajectory modeling using HYSPLIT • HYSPLIT-Hg atmos. fate and transport model • CMAQ-Hg atmospheric fate and transport model focus of today’s materials

13. AtmosphericMercury

14. Elemental Mercury: Hg(0) • ~ 95% of total Hg in atmosphere • not very water soluble • long atmospheric lifetime (~ 0.5 - 1 yr); globally distributed • Reactive Gaseous Mercury (“RGM”) • a few percent of total Hg in atmosphere • oxidized mercury: Hg(II) • HgCl2, others species? • somewhat operationally defined by measurement method • very water soluble • short atmospheric lifetime (~ 1 week or less); • more local and regional effects • Particulate Mercury (Hg(p) • a few percent of total Hg in atmosphere • not pure particles of mercury… • (Hg compounds associated with atmospheric particulate) • species largely unknown (in some cases, may be HgO?) • moderate atmospheric lifetime (perhaps 1~ 2 weeks) • local and regional effects • bioavailability? Three “forms” of atmospheric mercury

15. Hg(0) Hg(II) Hg(p) Wet and dry deposition of Hg(0), Hg(p), Hg(II) watershed processing We need to understand Hg in the environment enough to be able to fix the problem Many scientific disciplines need to work in collaboration to achieve this understanding

16. Freemont Glacier, Wyoming source: USGS, Shuster et al., 2002 Natural vs. anthropogenic mercury? Studies show that anthropogenic activities have typically increased bioavailable Hg concentrations in ecosystems by a factor of 3-10

17. For mercury, how important is atmospheric deposition relative to other loading pathways?

18. Figure 2. Estimated 1999 U.S. Atmospheric Anthropogenic Mercury Emissions

19. Figure 5. Geographic Distribution of Estimated Anthropogenic Mercury Emissions in the U.S. (1999) and Canada (2000)

20. Geographic Distribution of Largest Anthropogenic Mercury Emissions Sources in the U.S. (1999) and Canada (2000)

21. Emissions of Ionic Mercury (RGM) from Different AnthropogenicSource Sectors in Great Lakes States and Provinces (~1999-2000)[Amounts (kg/yr) shown]

22. Modeling the Fate and Transportof AtmosphericMercury

23. Elemental Mercury: Hg(0) Reactive Gaseous Mercury: RGM Particulate Mercury: Hg(p) Upper atmospheric halogen-mediated heterogeneous oxidation? Polar sunrise “mercury depletion events” Br cloud CLOUD DROPLET Hg(II) reducedto Hg(0) by SO2 “DRY” (low RH) ATMOSPHERE: Hg(0) oxidized to RGM by O3, H202, Cl2, OH, HCl Adsorption/ desorption of Hg(II) to /from soot Hg(p) Primary Anthropogenic Emissions Hg(0) oxidized to dissolved RGM by O3, OH, HOCl, OCl- Re-emission of natural AND previously deposited anthropogenic mercury Dry and Wet Deposition Atmospheric Fate Processes for Hg

24. Atmospheric Chemical Reaction Scheme for Mercury

27. 1996 Results for theGreat Lakes

29. Model-predicted deposition to Lake Michigan is consistent with empirical, measurement-based estimates from Lake Michigan Mass Balance Study

30. Comparison of model-estimated deposition to Lake Michigan (1996) withthat estimated in the Lake Michigan Mass Balance Study (1994-95)

31. 1999 Results for theGreat Lakes

32. Methodology for 1999 Updates • Modeling methodology outlined in Cohen et al., 2004; • 1996 meteorology used, with updated emissions inventory data • Only anthropogenic sources in the U.S. and Canada are considered • U.S. point & area emissions: EPA 1999 National Emissions Inventory • Top contributing sources checked and updated using Great Lakes Regional Toxics Inventory and other sources • Mobile source emissions estimates from 1996 NEI (1999 not available) • Canadian point & area emissions from 1995 Environment Canada inventory • Top contributing sources updated using 2000 NPRI

33. Emissions sources which are among the top-25 model-estimated contributors to one or more of the Great Lakes Note: does not include 4 metallurgical facilities outside the region

34. Emissions sources which are among the top-25 model-estimated contributors to one or more of the Great Lakes

35. Examples of some detailed 1999 results for Lake Michigan

36. Figure 35-A. Geographical Distribution of 1999 Direct Deposition Contributions to Lake Michigan (entire domain)

37. Figure 35-B. Geographical Distribution of 1999 DirectDeposition Contributions to Lake Michigan (regional view)

38. Figure 35-C. Geographical Distribution of 1999 DirectDeposition Contributions to Lake Michigan (more local view)

39. Figure 36. Emissions and Deposition Contributions from Different Distance Ranges Away From Lake Michigan

40. Top 25 Contributors to 1999 Hg Deposition Directly to Lake Michigan

41. EMEP Hg Model Intercomparison Project

42. EMEP Hg Model Intercomparison Projecthttp://www.msceast.org • Phase 1 (report and manuscript complete): • comparison of droplet chemistry modules • Phase 2 (report complete; manuscript in preparation): • comparison of predictions of ambient concentrations of Hg(0), RGM, and Hg(p) • for short-term episodes (~3-weeks) • Phase 3 (work in progress): • monthly wet and dry Hg deposition at ~10 sites • simple source-apportionment estimates for impact of in-country vs. other sources (for UK, Poland, Italy)

44. Measured and Simulated Total Gaseous Mercury at Neuglobsow during the 1995 episode

45. Measured and Simulated Total Particulate Mercury at Neuglobsow during the 1999 episode

47. A multi-mediamercury modeling project is just beginning

48. MULTI-MEDIA MERCURY MODELING PROJECT Update for the International Air Quality Planning Board January 26, 2005 Principal Investigators: Dr. Mark Cohen, NOAA Dr. Panos Georgopoulos, EOHSI Dr. John Johnston, USEPA Dr. Elsie Sunderland, USEPA

49. Multi-Media Hg Modeling System Emissions Meteorology * at each time step (e.g. 1 hour), the atmospheric and aquatic fate models communicate, and together, estimate the transfer of each mercury species across the air-water interface Atmospheric Model (HYSPLIT) Linkage program at air-water interface* Aquatic Fate and Cycling Model Food Chain & Bioaccumulation Model Exposure and Health Risk Models (MENTOR)

50. Additional details regarding the use of the NOAA HYSPLIT model for atmospheric mercury