Mercury hemispheric modelling: EMEP experience...TF HTAP 2nd Meeting, Moscow 2006 МСЦ-В MSC-E...

TF HTAP 2nd Meeting, Moscow 2006

Mercury hemispheric modelling: EMEP experience

Oleg TravnikovEMEP/MSC-E

МСЦ-В

MSC-E

TF HTAP 2nd Meeting, Moscow 2006МСЦ-В

MSC-E

Outline

Processes affecting the intercontinental transport and deposition of Hg

Long-term monitoring of Hg

Hemispheric Hg modelling within EMEP

Evaluation of model uncertainty


MSC-E

What are the pathways of Hg intercontinental transport?

Hg0

Hg0

HgII

Continent A Continent B

Hg0 HgIIOxidation

HgII

Hg0

HgII

HgIIHg0

GEM vertical profiles in the Arctic (Banic et al., 2003)

0

1

2

3

4

5

6

7

8

Altit

ude

(km

)


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Major atmospheric processes

Anthropogenic and natural emissions


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ReRe--emissionemission of Hgof Hg

Assimilation of observationsAssimilation of observationsMultiMulti--compartment compartment modellingmodelling

Natural emissionsNatural emissions of Hgof Hg

Hg emissions

Anthropogenic emissionsAnthropogenic emissions of Hg of Hg (1990, 1995, 2000)(1990, 1995, 2000)

CGEIC website CGEIC website www.ortech.ca/cgeicwww.ortech.ca/cgeic//

AMAP website AMAP website wwwwww..amapamap..nono//ResourcesResources//HgEmissionsHgEmissions

MSCMSC--E estimatesE estimatesEMEP/MSCEMEP/MSC--E Report 6/2002E Report 6/2002


MSC-E



Gas-phase and aqueous-phase chemistry


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Atmospheric chemistry

Major uncertainties:

Uncertainty of the reaction constants

Reaction RateGas-phase reactions cm3 molec-1 s-1

(3 – 490) · 10-20

(8.7 – 9) · 10-14

8.9 · 10-19

2.6· 10-18

< 9 · 10-17

(7.6 – 100) · 10-13

3.2 · 10-12

(1 – 100) · 10-15

Aqueous-phase reactions M-1 s-1

4.7 · 107

2.0 · 109

2.09 · 106

0.273

0.196

Texp(31.971T-12595)/T s-1

<< 10-4 s-1

3 · 10-7 s-1

1.99 · 106

0.279

1.7 · 104 s-1

)(),()()( ggsgg OHgOOHg 230 +→+

productsIIHgOHHg gg +→+ )()()( 220

productsIIHgClHg gg +→+ )()()( 20

productsIIHgClHg gg +→+ )()()(0

productsIIHgOHHg gg +→+• )()()(0

productsIIHgBrHg gg +→+ )()()( 20

productsIIHgBrOHg gg +→+ )()()(0

productsIIHgBrHg gg +→+ )()()(0

)()()( VISHgHgSO aqaq +→ 03

)()( )()( VISHgSOHg aqaq +→− 0223

productsHgUVOHHg aqaq +→+ 02 )()()(

productsHgHOIIHg aqaqaq +→+ • 02 )()()()(

productsHgOHg aqaqaq +→+ +23

0)()()(

productsHgOHHg aqaqaq +→+ +• 20)()()(

−−+ ++→+ OHClHgHOClHg aqaqaq20

)()()(

−−+− ++→+ OHClHgOClHg aqaqaq20

)()()(

−−+ ++→+ OHBrHgHOBrHg aqaqaq20

)()()(−−+− ++→+ OHBrHgOBrHg aqaqaq

20)()()(

−+ +→+ BrHgBrHg aqaqaq 222

0)()()(

Chemical transformations of Hg (Lin et al., 2006)


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Unknown products of the reactions. What is RGM?


(3 – 490) · 10-20

(8.7 – 9) · 10-14

8.9 · 10-19

2.6· 10-18

< 9 · 10-17

(7.6 – 100) · 10-13

3.2 · 10-12

(1 – 100) · 10-15


4.7 · 107

2.0 · 109

2.09 · 106

0.273

0.196

Texp(31.971T-12595)/T s-1

<< 10-4 s-1

3 · 10-7 s-1

1.99 · 106

0.279

1.7 · 104 s-1

)(),()()( ggsgg OHgOOHg 230 +→+









)()( )()( VISHgSOHg aqaq +→− 0223




0)()()(



)()()(


)()()(



20)()()(


0)()()(



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Unknown products of the reactions. What is RGM?

Unknown role of aqueous sorption by insoluble particles


(3 – 490) · 10-20

(8.7 – 9) · 10-14

8.9 · 10-19

2.6· 10-18

< 9 · 10-17

(7.6 – 100) · 10-13

3.2 · 10-12

(1 – 100) · 10-15


4.7 · 107

2.0 · 109

2.09 · 106

0.273

0.196

Texp(31.971T-12595)/T s-1

<< 10-4 s-1

3 · 10-7 s-1

1.99 · 106

0.279

1.7 · 104 s-1

)(),()()( ggsgg OHgOOHg 230 +→+









)()( )()( VISHgSOHg aqaq +→− 0223




0)()()(



)()()(


)()()(



20)()()(


0)()()(



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Wet and dry depositions


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Deposition processes

Peculiarities of Hg removal:

Close connection with emissions speciation and atmospheric chemistry

Hg emissionsGEM RGM+TPM

Hg depositionsfrom GEM emissions from RGM and TPM

emissions

Dry deposition of Hg0

Hg depositions to forest (accumulation in foliage)


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0

10

20

30

40

50

60

70

Steink

reuz,

DELe

hsten

bach

, DE

Urani, F

ISva

rtberg

et, FI

Hg

depo

sitio

n, μ

g/m

2 /y

Throughfall

Model

Modelled vs. measured Hg deposition to forest (Munthe et al., 2005)

0

10

20

30

40

50

60

70

Steink

reuz,

DELe

hsten

bach

, DE

Urani, F

ISva

rtberg

et, FI

Hg

depo

sitio

n, μ

g/m

2 /y

LitterfallThroughfallModel

Deposition processes

Peculiarities of Hg removal:

Close connection with emissions speciation and atmospheric chemistry

Dry deposition of Hg0

Hg depositions to forest (accumulation in foliage)


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Wet and dry depositions

Air-surface exchange


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Long-term monitoring of HgHg monitoring sites in the Hg monitoring sites in the

Northern HemisphereNorthern Hemisphere

Air conc. Wet DryEMEP GEM, HgP + –NADP/MDN – + –CAMNet GEM + –

Measuring Hg parameters

- air concentration- wet deposition - air conc. & wet deposition

0

10

20

30

40Hg concentration in precipitation, ng/L

`

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Lista, Norway (1990-2003)


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EMEP region

Hemispheric model (MSCE-HM-Hem)

Coverage – Northern Hemisphere

Resolution – 2.5°×2.5°

Regional model (MSCE-HM)

Coverage – EMEP region

Resolution – 50×50 km2

EMEP mercury transport models

One-way nesting


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Hg intercontinental transport

Contribution of non-Europeansources to Hg depositions in the NH

25-60% of Hg depositions in Europe comes from global sources

EMEP region

Hg deposition to Germany

Hg deposition to the UK

Belgium3%

France8%

Others8%

Natural (Europe)

1%

Germany49%

Netherlands7%

Global sources24%

UK29%

France2%

Others3%

Germany4%

Natural (Europe)

1%

Netherlands1%

Global sources60%


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Total annual Hg deposition in Total annual Hg deposition in the the Northern HemisphereNorthern Hemisphere

61%

15%

5% 3%

12%4%

0

20

40

60

80

100

120

Euro

pe

Asi

a

Nor

thA

mer

ica

Afri

ca

Oce

ans

Sout

h.H

em.

Tota

l Hg

depo

sitio

n, t/

y

NaturalAnthropogenic

Hg deposition in Hg deposition in EuropeEurope


MSC-E



14%

24%

33%

3%

18%

8%

0

20

40

60

80

Euro

pe

Asi

a

Nor

thA

mer

ica

Afri

ca

Oce

ans

Sout

h.H

em.

Tota

l Hg

depo

sitio

n, t/

y


Hg deposition in Hg deposition in North AmericaNorth America


MSC-E


Pollution of remote regions

7%

24%

4%

10%

33%

22%

0

20

40

60

80

100

Eur

ope

Asi

a

Nor

thA

mer

ica

Afri

ca

Oce

ans

Sou

th.

Hem

.

Tota

l Hg

depo

sitio

n, t/

y


Hg deposition in the Hg deposition in the ArcticArctic


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Model evaluation

Sensitivity analysis

Evaluation vs. measurements

Models-to-model intercomparison


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Sensitivity analysis (regional)GEM concentration Hg total deposition

0.0 0.2 0.4 0.6 0.8 1.0

Boundary (GEM)Anthrop. emission

n speciationd re-emission

Cloud water pHidation by O3 (gas)

Wet depositionDry deposition

Cloud LWCnry's constant Hg0xidation by O3 (aq)

Upper boundarydation by OH (gas)y deposition (fog) deposition (GEM)Aerosol solubility

Sensitivity coefficient

EmissioNatural an

Ox

HeO

OxiDr

Dry

0.0 0.2 0.4 0.6 0.8 1.0

Boundary (GEM)Anthrop. emission

Emission speciationNatural and re-emission

Cloud water pHOxidation by O3 (gas)

Wet depositionDry deposition

Cloud LWCHenry's constant Hg0Oxidation by O3 (aq)

Boundary (TPM)Oxidation by OH (gas)

Dry deposition (fog)Dry deposition (GEM)

Aerosol solubility

Sensitivity coefficient


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Sensitivity analysis (regional)

Input parameters εx

Anthropogenic emissions 50%

40%

Natural emission and re-emission 90%

Eddy diffusion coefficient 50%

Aerosol solubility 50%

75%

75%

20%

50%

50%

Oxidation rate by OH 75%

Oxidation rate by Cl2 90%

Reduction rate in aqueous phase 50%

Hg ion-chloride equilibrium constant 50%

Solution-adsorption equilibrium constant 50%

pH of cloud water 20%

Chloride ion concentration 90%

Speciation of anthropogenic emission

Wet deposition coefficient

Dry deposition velocity

Boundary concentration GEM

Liquid water content

Oxidation rate by O3

Uncertainty of input parameters

0

20

40

60

80

100

Conc in air Conc in prec Total depos

Unc

erta

inty

, %

Estimated model uncertainty


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- air concentrations- wet deposition flux

TGM concentrationTGM concentration

Cmod = 0.88 Cobs

Rcorr = 0.940.0

1.0

2.0

3.0

0.0 1.0 2.0 3.0

Observed, ng/m3

Mod

el, n

g/m

3 +30%

-30%

Fmod = 1.13 Fobs

Rcorr = 0.510

5

10

15

20

0 5 10 15 20

Observed, g/km2/y

Mod

el, g

/km

2 /y +50%

-50%

Hg wet depositionHg wet deposition

Measurement data on Hgpart and RGM concentrations and Hg dry deposition is required

Spatial variation (annual mean values)


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Lista

Long-term trends (1990-2003)

Lista (NO99)

De Zilk (NL91)

De Zilk

NO99 NL91

Correlation 0.48 0.53

-9% -1%Bias

Monthly statistics

0

10

20

30

40Model ObservedHg concentration in precipitation, ng/L

`

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

0

10

20

30

40

50

Model ObservedHg concentration in precipitation, ng/L

`

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003


MSC-E

Hg models intercomparisonEMEP EMEP intercomparison intercomparison study for Hg modelsstudy for Hg models

Model Institution Country

EMAP Institute of Meteorology and Hydrology Bulgaria

GRAHM Environment Canada Canada

ADOM GKSS-Forschungszentrum Germany

CMAQ US EPA USA

DEHM Environmental Research Institute Denmark

HYSPLIT NOAA USA

CAM Swedish Environmental Research Institute Sweden

MCM Atmospheric and Environmental Research, Inc. USA

MSCE-HM MSC-E EMEP

MSCE-HM-Hem MSC-E EMEP

Stage I. Comparison of chemical modules

Stage II. Comparison with short-term field measurements

Stage III. Comparison of long-term results and atmospheric budgets


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Hg models intercomparison

IntercomparisonIntercomparison of Hg of Hg dry depositiondry depositionLocation of monitoring sitesLocation of monitoring sites

Stage III. Comparison of long-term modelling results

0.0

0.5

1.0

1.5

DE01DE09NL9

1NO99SE02SE11SE12SE05 FI96

Dry

dep

ositi

on, g

/km

2 /mn

ADOM CMAQ DEHMEMAP GRAHM HYSPLITMSCE-HM MSCE-HM-Hem

August, 1999


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Hg models intercomparison

Atmospheric budgetAtmospheric budget of Hg deposition to Polandof Hg deposition to Poland

0

200

400

600

800

1000

1200

ADOM EMAP MSCE-HM

MSCE-HM-Hem

HYSPLIT DEHM

Tota

l dep

ositi

on, k

g/m

n

National EuropeanGlobal European+global

August 1999

Stage III. Comparison of long-term modelling results


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Conclusions

Current understanding of Hg atmospheric processes is incomplete and requires further research

In spite of significant uncertainties, available Hg models reflect general Hg atmospheric cycle and can be used for evaluation of the intercontinental transport

Model predictions show that the intercontinental transport significantly contribute to Hg depositions (40% in Europe and 70% in North America)

Evaluation of the model uncertainty can include sensitivity analysis, comparison with long-term measurements and model intercomparisons


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Further research

Development of global Hg emission inventories from anthropogenic (speciation) and natural sources

Refinement of Hg atmospheric chemistry (reaction constants, products etc.)

Monitoring of Hg species (Hgpart, RGM) and dry deposition fluxes

Extension of the Hg models intercomparison activities to the hemispheric scale

Application of multi-compartment modelling for evaluation of Hg cycling on hemispheric/global scale

Mercury hemispheric modelling: EMEP experience...TF HTAP 2nd Meeting, Moscow 2006 МСЦ-В MSC-E...

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Transcript of Mercury hemispheric modelling: EMEP experience...TF HTAP 2nd Meeting, Moscow 2006 МСЦ-В MSC-E...