# Presentation: 865390

## NOAA Collaborative Mercury Sites

**Three sites committed **
**to speciated mercury ambient concentration measurement network**

**Grand Bay**
**NOAA**

**NOAA Collaborative Mercury Sites**

## Beltsville, MD

**Beltsville, MD**
**CASTNet Site**

**100 miles **
**from DC**

**Bremo**

**Beltsville monitoring site**

**Morgantown**

**Chalk Point**

**Dickerson**

**Possum Point**

**Eddystone**

**Arlington - Pentagon MSW Incin**

**Brandon Shores **
**and H.A. Wagner**

**Montgomery County**
**MSW Incin**

**Harford County MSW Incin**

## Coal-fired power plants in MD, VA, PA, and DE with the largest projected differences between 2010 base  and 2010 Clean Air Interstate Rule (CAIR) emissions

**Coal-fired power plants in MD, VA, PA, and DE with the largest projected differences between 2010 base  and 2010 Clean Air Interstate Rule (CAIR) emissions**

## Status of Atmospheric Measurements

| Measurement |
| --- |
| Elemental mercury |
| Fine particulate mercury |
| Reactive gaseous mercury |
| Sulfur dioxide |
| Ozone |
| Carbon Monoxide |
| Nitrogen Oxides (NO, NOy) |
| Wind speed |
| Wind Direction |
| Relative Humidity |
| Temperature |
| Precipitation |
| SO42-, NO3-, NH4+, HNO3, SO2 (Weekly)  |
| Total mercury in precipitation (weekly) |
| Major ions in precipitation (weekly) |

**Status of Atmospheric Measurements**
** ****at Beltsville, MD CASTNet Site**

## Tekran Speciation System

**Tekran Speciation System**
**Installed System 1 (NOAA) Nov. 7, 2006**
**   ****Height of Inlet: 3.75 m above ground**
**	**** ****	****	****      ****0.5 m above trailer**
**	**
**Installed second system**
**	****(System 2-NOAA) Jan 26, 2007**
**System 1 removed April 27, 2007**
**Install System 3 (EPA) June 1, 2007**
**Remove System 2 August 17, 2007**

## Tekran Deployment Timeline -Beltsville

## NOY

**Site is influenced by vehicular traffic in Washington Metropolitan area, particularly pronounced during the morning rush hour. Higher boundary layer in the afternoon/evening dilutes vehicular emissions. **

**80 ppb**

**60**

**40**

**NO****Y**

## CO

**Concentrations of CO at the site also reflect the impact of  vehicular emissions, but the efficacy of emission controls in the past decade have reduced the strength of this signal.**

**400**

**200**

**600 ppb**

**CO**

## SO2

**Site is also influenced by **
**point-source emitters in the region. Higher concentrations in Fall and Winter reflect lower boundary layer heights, slower conversion of SO****2**** to SO****4****2-**

**10**

**20**

**30**

**40 ppb**

**SO****2**

## Photochemical ozone generation in the Spring and Summer leads to elevated concentrations in mid-day. Note the later time of boundary layer breakup in Fall and Winter, as evidenced by later onset of daytime increase. 

**Photochemical ozone generation in the Spring and Summer leads to elevated concentrations in mid-day. Note the later time of boundary layer breakup in Fall and Winter, as evidenced by later onset of daytime increase. **

## Elemental Hg0

**Elemental Hg0**

## Elemental Mercury (Hg0) at Beltsville

**1**

**2**

**3**

**4 ng m****-3**

**Elemental Mercury (Hg****0****) at Beltsville**

**As expected, Hg0 at Beltsville shows no diurnal pattern, little dependence on WD, consistent with a long-lived, ubiquitous, and well mixed trace species. Note that emission source regions match those for SO****2****, NO****Y****, CO**

## Hg-P

**Hg-P**

**(a few peaks > 500 pg m-3 not shown)**

## Particulate Mercury (Hg-P)

**Little diurnal variation in Hg-P concentrations, with some evidence of entrainment of higher concentrations aloft beginning in the morning, after the breakup of the nocturnal inversion. Spikes due to influence of a few high-concentration events. **

**Particulate Mercury (Hg-P)**

## Particulate Mercury (Hg-P)

**All Data**

**Winter**

**Hg-P concentrations are highest during NE flow, consistent with the distribution of local/regional sources. Concentrations show some association with SO****2****, especially in Winter. Power plants emit little Hg-P.**

**Particulate Mercury (Hg-P)**

## RGM

**RGM**

**RGM concentrations generally < 20 pg m****-3****, with more frequent peaks in concentration than was seen for Hg-P**

## Reactive Gaseous Mercury (RGM)

**More pronounced diurnal variation in RGM concentrations, again showing evidence of entrainment of higher  concentrations aloft with the breakup of the nocturnal inversion. Large seasonal differences may point to secondary (photochemical) source of RGM as well.**

**Reactive Gaseous Mercury (RGM)**

## Association of high RGM with high O3 and aged air masses (low NO/NOY ratios) suggests that secondary production of RGM may be occurring. 

**Spring**

**Beltsville**

**Spring**

**All Data**

**Association of high RGM with high O****3**** and aged air masses (low NO/NO****Y**** ratios) suggests that secondary production of RGM may be occurring. **
**However, high concentrations of RGM may arise from primary emissions from sources a few hours away – and the air masses are somewhat aged on arrival at the site.**

**increasing air mass age**

## Reactive Gaseous Mercury (RGM)

**Directionality of [RGM] shows lobes to the SW and NE, coincident with known local sources of mercury and other primary trace species.**
**RGM is most closely associated with SO****2**** at Beltsville (Summer) suggesting that point-source emissions also play an important role in influencing RGM concentrations at the site**

**Summer**

**Reactive Gaseous Mercury (RGM)**

## Grand Bay NERR Site

**Barry**

**Holcim Cement**

**NOAA Grand Bay**
** ****NERR Hg site**

**Weeks**
**Bay**

**OLF**

**Molino**

**Pace**

**Ellyson**

**Jack Watson**

**AL24**

**AL02**

**Crist**

**Pascagoula **
**MSW incin**

**haz waste incin**

**paper manuf**

**paper manuf**

**Victor J. Daniel**

- Mobile
- Bay

- Mobile

- Pascagoula

**Mississippi**

**Alabama**

- MS 22

**Grand Bay NERR Site**

## Status of Atmospheric Measurements

| Measurement | Type | Start Date |
| --- | --- | --- |
| Elemental mercury | A | Sept 2006 |
| Fine particulate mercury | A | Sept 2006 |
| Reactive gaseous mercury | A | Sept 2006 |
| Sulfur dioxide | A | Oct 2006 |
| Ozone | A | Oct 2006 |
| Carbon Monoxide | A | Oct 2006 |
| Nitrogen Oxides (NO, NOy) | A | * |
| Wind speed | C | Feb 2007 |
| Wind Direction | C | Feb 2007 |
| Relative Humidity | C | Feb 2007 |
| Temperature | C | Feb 2007 |
| Precipitation | C | Feb 2007 |
| Total mercury in precipitation | B | * |
| Major ions in precipitation | B | * |

*Type of Measurement:*
- A = concentration in ambient air
- B = concentration in precipitation
- C = meteorological parameter

**Status of Atmospheric Measurements**
** ****at Grand Bay NERR, Mississippi**

- * to be established

**4 m sampling height**

## Elemental Mercury (Hg0) at Grand Bay

**As expected, with a few exceptions Hg****0**** concentrations show **
**little or no diurnal variation or dependence on wind direction**

**Elemental Mercury (Hg****0****) at Grand Bay**

## Overnight Event

**Overnight Event**
**Feb. 28-March 1**
**Strong correlation between Hg****0**** and CO, O****3****.**
**Suggests combustion (natural sources?) and transport from source regions to **
**West. RGM, Hg-P **
**ca 20 pg m****-3**
**during episode**

## Particulate Mercury (Hg-P)

**All Data**

**All Data**

**With the exception of a few well-defined transport events, Hg-P displays no consistent relationship with wind direction, and exhibits little or no correlation with other trace species**

**Particulate Mercury (Hg-P)**

## Strongest correlations seen between RGM and O3, most of which is driven by seasonal dependence –RGM concentrations are highest, relationship with O3 is strongest in Spring.

**Strongest correlations seen between RGM and O****3****, most of which is driven by seasonal dependence –RGM concentrations are highest, relationship with O****3**** is strongest in Spring.**

**Spring**

**All Data**

## Association of peak RGM with low RH and CO concentrations typical of continental influence suggests highest Spring peaks of RGM are seen in post-frontal activity, with transport from upwind continental sources to the North. 

**Association of peak RGM with low RH and CO concentrations typical of continental influence suggests highest Spring peaks of RGM are seen in post-frontal activity, with transport from upwind continental sources to the North. **
**What is the role of  downward mixing of upper-tropospheric air, which contains elevated RGM, O****3****, and lower CO and RH ? **

**Spring**

**Spring**

**Spring**

**All Data**

**Weaker RGM – SO****2**** correlation at Grand Bay than at Beltsville suggests:**
** **
**A mix of primary sources with varying emission characteristics**
**A mix of primary and secondary sources of RGM**
**Different chemical processing and removal rates of SO****2**** and RGM during transport**
**Lack of correlation –RGM and Hg-P suggests different**
**sources and/or removal rates**
**of these species**

## As at Beltsville, significant diurnal patterns seen in RGM,  but amplitude of diurnal Hg-P profile is much smaller.

**As at Beltsville, significant diurnal patterns seen in RGM,  but amplitude of diurnal Hg-P profile is much smaller.**
**Highest RGM and Hg-P concentrations seen in Spring. At Beltsville, Hg-P peaks in the winter, and Spring-Summer differences between RGM and Hg-P are small**

## Similarity to O3 and SO2 diurnal profiles confirms the importance of downward mixing in the development of the daytime boundary layer, but photochemical (secondary) production of RGM is also possible

**Similarity to O****3**** and SO****2**** diurnal profiles confirms the importance of downward mixing in the development of the daytime boundary layer, but photochemical (secondary) production of RGM is also possible**

## Summary and Conclusions – 

**At both sites, RGM exhibits a more pronounced diurnal profile than Hg-P, but both profiles are coincident with O****3**** and SO****2**** peaks, suggesting downward mixing of an aloft reservoir upon the breakup of the nocturnal boundary layer. In situ production of RGM may also be contributing. RGM peaks in the Spring at Grand Bay, in Spring and Summer at Beltsville. Hg-P is higher in Winter at Beltsville.**
**At Beltsville, RGM correlates most closely with SO****2**** in Summer, suggesting the dominance of nearby (primary) emissions. However, RGM is also associated with elevated O****3 ****and  low NO/NOy ratios, suggesting that  secondary production may also be important**

**Summary and Conclusions – **
**Interpretation of Ambient Measurements**

## Summary and Conclusions – 

**These results suggest RGM is transported from northerly continental sources following cold-frontal penetration in Spring. Reduced frequency of cold frontal passage at the site in Summer leads to lower RGM levels, more sporadic transport to the site from upwind sources.**

**Summary and Conclusions – **
**Interpretation of Ambient Measurements**
**(continued....)**

## Deposition Estimates

## Preliminary Deposition Estimates -Beltsville

**assumes V****d**** = 2.5 cm s****-1**** and 0.3 cm s****-1**** mid day average**
**	****	****	****	****	****	****Fluxes (ng m****-2**** day****-1****)**
**	****	****	****	****	****Fall****	****Winter  Spring  Summer**
**Dry Dep, Beltsville (2006-2007)****	****	****   7.8****	****   22.3****	****     18.2**
**Wet Dep, Beltsville (2005-2006)****	****35.4****	**** ****13.9****	****   13.0****	****     54.8     **

**Preliminary Deposition **_**Estimates**_** -Beltsville**

## Preliminary Deposition Estimates -Grand Bay

**RGM + Hg-P Dry Deposition (ng m****-2**** day****-1****);**
**assumes V****d**** = 2.5 cm s****-1**** and 0.3 cm s****-1**** mid day average**
**	****	****	****	****	****	****Fluxes (ng m-2 day-1)**
**	****	****	****	****	****Fall****	****Winter  Spring  Summer**
**Dry Dep, Grand Bay (2006-2007)****	****  ****5.4****	****   4.3****	****   14.2****	****       8.6**
**Wet Dep, AL24 (2005-2006)****	****	****13.5****	**** 24.8****	****   31.6****	****     34.6**
**Wet Dep, MS22 (2005-2006) ****	****11.9****	**** 28.2****	****   28.5****	****     65.3**
**Wet Dep, AL02 (2005-2006)****	****	****24.7****	**** 21.6****	****   31.3****	****     34.6**

**Preliminary Deposition **_**Estimates**_** -Grand Bay**

## Summary and Conclusions - Deposition

**Dry deposition estimates, when compared with nearby MDN deposition records, suggest that dry deposition sometimes dominates at the Beltsville site, depending on season.**
**At Grand Bay, wet deposition dominates the removal of reactive mercury species, especially in Winter. **
**If substantial Hg exists in the coarse aerosol fraction, however, the reported dry deposition fluxes are under-estimated.**

**Summary and Conclusions - Deposition**

## Trajectory Analysis 

**Examples: Beltsville**

## Beltsville Episode January 7, 2007

## Slide 38

## Slide 39

## Slide 40

## Slide 41

## Slide 42

## Slide 43

## Slide 44

## Slide 45

## Slide 46

## Slide 47

## Beltsville Episode May 18, 2007

## Slide 49

## Slide 50

## Slide 51

## Slide 52

## Slide 53

## Slide 54

## Slide 55

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## Slide 57

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## Slide 62

## Slide 63

## Slide 64

## Trajectory Analysis 

**Examples: Grand Bay**

## Higher RGM Associated with N-E trajectories

**Higher RGM Associated with N-E trajectories**

**Peak ~ 50 pg m****-3**

**Peak ~ 118 pg m****-3**

**Peak ~ 55 pg m****-3**

**Peak ~ 105 pg m****-3**

**Peak ~ 100 pg m****-3**

**Peak ~ 65 pg m****-3**

## Lower RGM in Maritime trajectories

**Lower RGM in Maritime trajectories**

**Peak ~ 7 pg m****-3**

**Peak ~ 2 pg m****-3**

**Peak ~ 10 pg m****-3**

## Grand Bay 

- Grand Bay
- Episode
- March 6, 2007

- March 6

- March 7

## March 7

- March 6

## March 6

- March 7

## March 7

- March 6

## March 7

- March 6

## March 7

- March 6

## March 7

- March 6

## March 7

- March 6

## March 7

- March 6

## March 7

- March 6

## March 7

- March 6

## March 7

- March 6

## March 7

- March 6

## March 7

- March 6

## March 7

- March 6

## Grand Bay 

- Grand Bay
- Episode
- Nov 18, 2006

## Slide 84

## Slide 85

## Slide 86

## Slide 87

## Slide 88

## Slide 89

## Slide 90

## Slide 91

## Slide 92

## Slide 93

## Precision, QA/QC Studies

## Tekran Speciation System

**Tekran Speciation System**
** ****Installed System 1 (NOAA) Nov. 7, 2006**
**  ****Height of Inlet: 3.75 m above ground**
**	****	****     ****0.5 m above trailer**
**	**
** ****Installed second system **
**  ****(System 2-NOAA) Jan 26, 2007**
** ****System 1 removed April 27, 2007**
** ****Install System 3 (EPA) June 1, 2007**
** ****Remove System 2 August 17, 2007**

## Tekran Speciation Systems

**QA/QC Studies**

** ****Periodic deployment of duplicate systems**
**	****Jan. 26-Apr. 27, 2007**
**	****June 1-Aug. 17, 2007**
** ****Precision and accuracy of independent**
**  ****systems**
** ****Investigation of aerosol size segregation of**
**  ****Hg-P**

## Tekran Deployment Timeline -Beltsville

## Slide 98

## Slide 99

## Slide 100

## Slide 101

## Monitoring Sites:

**Next Steps**

## Beltsville

**Addition of 10 m walk up scaffold**
**Migration to new shelter?**
**Acquisition of second Tekran system**
**	****Synchronous sampling –precision, ****	****QA/QC studies, etc.**
**	****Asynchronous sampling for true ****	****continuous measurements**
**	****	**

## Grand Bay

**Migration from old trailer and site to new trailer at permanent site (water’s edge, 2 miles  distant)**
**Addition of 10m walk-up scaffold**
**Addition of second Tekran System**
**Synchronous sampling –precision, QA/QC studies, investigation of Hg/aerosol size, etc.**
**Asynchronous sampling for true continuous measurements**
**Addition of NO/NO****Y**** monitor**

## Pictures of Permanent Monitoring Site –Grand Bay

**Pictures of Permanent Monitoring Site –Grand Bay**

## Model Evaluation 

**and Improvement**

## Emissions Inventories

**Emissions Inventories**

**To evaluate and improve atmospheric models, emissions inventories must be:**
**Accurate for each individual source (especially for large sources), including variations **
**For the same time periods as measurements used for evaluation**
**For all forms of mercury **

**Atmospheric Monitoring**

**To evaluate and improve atmospheric models, atmospheric monitoring must be:**
**For air concentrations (not just wet deposition)**
**For all forms of mercury **
**For sites impacted by  sources (not just background sites)**
**At elevations in the atmosphere (not just at ground level)**

**?**

**Understanding and Decisions**

**?**

**?**

**Source-attribution; Scenarios**

**Understanding Trends**

**Inputs for Ecosystem Models**

**Deposition For Entire Region**

**Incin**

**Manuf**

**Fuel (not coal electric)**

**Hg Dep to Lake Michigan (g/km2-yr)**

**Coal-electric**

**Coal **
**Scenarios**

## Why do we need atmospheric mercury models?

**to get *****comprehensive source attribution***** information **
- 	...we don’t just want to know how much is depositing at any given location, we also want to know where it came from:
-  different source regions (local, regional, national, continental, global)
-  different jurisdictions (different states and provinces)
-  anthropogenic vs. natural emissions
-  different anthropogenic source types (power plants, waste incin., etc)
**to estimate *****deposition over large regions**** *
*	**...*because deposition fields are highly spatially variable,
- 	and one can’t measure everywhere all the time...
**to estimate *****dry deposition***
- 	... presently, dry deposition can only be estimated via models
**to evaluate *****potential consequences***** of alternative future emissions scenarios**

## Atmospheric models can potentially provide valuable deposition and source-attribution information.

**But... models have not been adequately evaluated, **
**so we don’t really know very well how good or bad they are...**

_***Challenges / critical data needs for model evaluation:***_
_***Ambient Monitoring Data***_
- speciated ambient concentrations at a number of different locations, both source-impacted and remote
-       	*(need RGM and Hg(p), not just total gaseous mercury)*
- wet deposition
_***Emissions inventories***_
-  complete, accurate, speciated
-  up-to-date (or at least for the same period as measurements)
-  temporal resolution better than annual (e.g., shut-downs, etc)

**Atmospheric models can potentially provide valuable deposition and source-attribution information.**
**But... models have not been adequately evaluated, **
**so we don’t really know very well how good or bad they are...**

## WET DEPOSITION 

**WET DEPOSITION **
** **_**complex**_** – *****hard to diagnose***
** **_**weekly**_** – *****many events***
** **_**background**_** – *****also need near-field***

**AMBIENT AIR CONCENTRATIONS **
_** **__**more fundamental**_** – *****easier to diagnose***
** **_**need continuous**_** – *****episodic source impacts***
** **_**need speciation**_** – *****at least RGM, Hg(p), Hg(0)***
** **_**need data at surface and above**_

## ?

***many ways to get the “wrong” answer – incorrect ***_***emissions***_***, incorrect t***_***ransport***_***, incorrect ***_***chemistry***_***, incorrect ***_***3-D precipitation***_***, incorrect ***_***wet-deposition algorithms***_***, etc..***

***models need ambient air concentrations first, and then if they can get those right, they can try to do wet deposition...***

**wet dep **
**monitor**

**ambient air **
**monitor**

- _Wet deposition is a very complicated multi-stage phenomena...__not ideal for atmospheric mercury model evaluation purposes _

**?**

**?**

**?**

## Ryaboshapko, A., et al. (2007). Intercomparison study of atmospheric mercury models: 1. Comparison of models with short-term measurements. Science of the Total Environment 376: 228–240. 

**http://www.arl.noaa.gov/data/web/reports/cohen/49_EMEP_paper_2.pdf**

## Total Gaseous Mercury (ng/m3) at Neuglobsow: June 26 – July 6, 1995

| EMEP Intercomparison Study of Numerical Models for Long-Range Atmospheric Transport of Mercury |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Intro-duction | Stage I | Stage II |  |  | Stage III |  |  | Conclu-sions |
|  | Chemistry | Hg0 | Hg(p) | RGM | Wet Dep | Dry Dep | Budgets |  |

**Total Gaseous Mercury (ng/m****3****) at Neuglobsow: June 26 – July 6, 1995**

## Total Particulate Mercury (pg/m3) at Neuglobsow, Nov 1-14, 1999

| EMEP Intercomparison Study of Numerical Models for Long-Range Atmospheric Transport of Mercury |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Intro-duction | Stage I | Stage II |  |  | Stage III |  |  | Conclu-sions |
|  | Chemistry | Hg0 | Hg(p) | RGM | Wet Dep | Dry Dep | Budgets |  |

**Total *****Particulate***** Mercury (pg/m****3****) at Neuglobsow, Nov 1-14, 1999**

## Reactive Gaseous Mercury at Neuglobsow, Nov 1-14, 1999

**Reactive Gaseous Mercury at Neuglobsow, Nov 1-14, 1999**

## Ryaboshapko, A., et al. (2007). Intercomparison study of atmospheric mercury models: 2. Modelling results vs. long-term observations and comparison of country deposition budgets. Science of the Total Environment 377: 319-333.

**http://www.arl.noaa.gov/data/web/reports/cohen/49_EMEP_paper_2.pdf**

## Overall Summary

**The different sites provide the opportunity to investigate the effects of differences in regional source distribution, atmospheric processes, geographic characteristics, etc. on the fate and transport of atmospheric mercury. However, additional sites are needed to provide a wider range of conditions.**
**Ancillary trace gas, aerosol, and meteorological measurements are critically needed to interpret mercury measurements.**
**Substantial progress is being  made on the development of Standard Operating Procedures (SOP) and Best Measurement Practices (BMP) , as well as QA/QC protocols.**
**A draft SOP / BMP document will be discussed and ratified later this week at a meeting in Chicago **

**Overall Summary**

## Overall Summary... continued

**Atmospheric mercury models are needed to provide source-attribution information and estimated impacts of alternative future scenarios, but models have not been adequately evaluated due to a lack of speciated ambient concentration data.**
**The emerging ambient monitoring network discussed today will provide this critically needed measurement data. **
**With these data, models will be able to systematically evaluated -- and improved if necessary -- allowing their results to be used with more confidence.**
**Moreover, the datasets will be available on an ongoing basis for ground-truthing  model results generated for policy analysis purposes. **

**Overall Summary... continued**