Geochemical cycling modeling

Abiotic multicompartmental modeling – examples from the EU POPCYCLING project

Biotic food chain modeling – examples from the AMAP project

N:\adm\arkiv\overhead\2006\CEE\Yale-8.ppt 1

Model Region

advectiveinflow

lossloss

sourcessources

evaporationevaporationdepositiondeposition

advectiveoutflow

lossloss

AtmosphereAtmosphere

Marine SystemMarine System

evaporationevaporationdepositiondeposition

Terrestrial SystemTerrestrial System

lossloss

run-offrun-off

The POPCYCLING-Baltic model aims to quantify the pathways of POPs from theterrestrial environment to the marine environment via atmosphere and rivers.

aquatic model catchment modelWater

Atmosphere

Vegetation

Water

FreshWater

Sediment

Soil

Sediment

system boundary

The system of a catchment model includes the drainage basin of the water body and the atmosphere above it.

T1 Bothnian Bay

T2 Bothnian Sea

T4 Neva

T3 Gulf of Finland

T5 Gulf of

Riga

T6 Southern

Baltic Proper

T7 Swedish

Baltic Proper

T8 Danish Straits

T9 Kattegat

T10 Skagerrak

C1 Coastal

Bothnian Bay

C2 Coastal

Bothnian Sea C4

Neva

C3 Coastal Gulf of Finland

C5 Gulf of

Riga

C6 Southern

Baltic Proper

C7 Swedish

Baltic Proper

C8 Danish Straits

C9 Kattegat

C10 Coastal

Skagerrak

O1 Open

Bothnian Bay

O2 Open

Bothnian Sea

O3 Open

Gulf of Finland

O6 Open

Skagerrak O4 OpenBaltic Proper

O5Bottom

water

A1 North

A2 East

A3 South

A4 West

Maps showing the compartmentalisation of the terrestrial (A), marine (B) and atmospheric (C) environment of the Baltic Sea drainage basin in the POPCYCLING-Baltic model. Each of the ten terrestrial units is represented by five compartment (agricultural soil, forest soil, forest canopy, fresh water,fresh water sediment), each of the marine units by a water and a sediment compartment.

agriculturalagriculturalsoilsoil

forestforestsoilsoil

forestforestcanopycanopy

fresh waterfresh water

coastalcoastalsedimentsediment

coastalcoastalwaterwater

open open waterwater

bottombottomwaterwater

bottombottomsedimentsediment

atmosphere

interphase transferdirect emissiondegradation lossadvection with air and water

Terrestrial Environment Marine Environment

fresh water sedimentfresh water sediment

Schematic representation of the types of environmental compartments in the POPCYCLING-Baltic model and how they are connected by diffusive and advective transport terms. A chemical can bereleased into six types of compartments, and degradation can occur in all types of media.

Water Mass Balance

POC Mass Balance

Contaminant Mass Balance

Air Mass Balance

Solving the mass balance for a POP requires the construction of mass balances for air,water and particulate organic carbon (POC).

North

East

South

WestO to W

W to O

E to O

O to E

O to N N to O

E to N N to E

W to S

S to W

O to S S to O

W to N

N to W

S to EE to S

Sixteen atmospheric advection rates are used to describe the movement of air across theBaltic Sea drainage basin in the POPCYCLING-Baltic model (O stands for “outside of the model system”).

0

5

10

15

20

25

30

35

0 50 100 150 200 250 300 350

Julian Day

air r

esid

ence

tim

e in

hou

rs

West

EastSouth

North

Seasonal variability of the residence time of air in the four atmospheric compartments of the POPCYCLING model. The residence time is lower in the Western air compartment because of its smaller size.

0123456789

1 2 3 4 5 6 7 8 9 10 11 12month

OH

con

cent

ratio

n in

105 c

m-3 South

West

East

North

Seasonal functions defining the OH radical concentration in the four atmosphericCompartments of the POPCYCLING model.

atmosphere

agriculturalsoil

forestsoil

forestcanopy

fresh water

wGFAwGAF

wGFB

wGEAwGAE

wGBA

wGBW wGEWwGWC

wGWAwGAW

Water Balance in the Terrestrial Environment

wGAF precipitation to canopywGFA evaporation from canopywGFB throughfall/stem flowwGBA evaporation from forest soilwGBW run-off/leaching from forest soilwGAE precipitation to agricultural soilwGEA evaporation from agricultural soilwGBW run-off/leaching from agricultural soilwGAW precipitation to fresh waterwGWA evaporation from fresh waterwGWC riverine run-off

Water fluxes between the compartments of a drainage basin.

winterspring

summerfall

winter

deciduous canopyseasonality caused by changes in atmospheric stabilityand by seasonality of canopy development

coniferous canopy and soilsseasonality caused by changes in atmospheric stability

deposition velocities

Schematic representation of the seasonal dependence of the deposition velocities in the terrestrial environment. During winter, summer average, i.e. maximum, values for vD are reduced by a factordescribing the relative stability of the atmosphere, and spring and fall defined as linear functionsconnecting summer and winter values.

litter fall

winterspring

summerfall

winter

deciduous

coniferous

canopy volume

winterspring

summerfall

winter

deciduous

coniferous

Schematic representation of the seasonal dependence of the volume of the forest canopy VFand the litter fall advection term GFB .

O156 m

24.5·10³ km²1371 km3

462 days

O2 73 m

62·10³ km²4528 km3

1084 days

O344 m

18.6·10³ km²820 km3

369 days

C5Gulf of Riga

22.7 m16.4·10³ km²

372 km3

2025 days

O5Bottom Water

38 m177·10³ km²

6722 km3

1668 days

14711000

249457

104207

139

255

37

67

510

Index Sub-Basinaverage depthsurface areawater volumeresidence time evaporation

precipitationriverine inflow

interbasin flow

2533

911

10

1130

1414

942

C25.8 m

22.9·10³ km²133 km3

46 days

964

106012

1395

C18.3 m

15·10³ km²125 km³47 days

876

9757

898

C7 Swedish Coast

7.9 m20.7·10³ km²

163 km3

45 days

1314

133212

1317

471

471

O4 Surface Water

30 m177·10³ km²

5307 km3

305 days

C6 Southern Coast

8.7 m32.2·10³ km²

280 km3

45 days16

1891

22822190

C35.7 m

11.6·10³ km²66 km3

43 days

526563

6

736

C4Neva1.0 m

0.3·10³ km²0.3 km3

1 day

108

310.2

0.277

Bothnian Bay

C8 Danish Straits

14.3 m20.1·10³ km²

288 km3

37 days

C9 Kattegat23.1 m

22.3·10³ km²515 km3

47 days

19291447

12

1629

11

148

O6255 m

26.4·10³ km²6730 km3

137 days

25732058

15585

14989

NorthSea 8

18

C10 7.8 m

7.0·10³ km²55 km3

47 days

350422

4

571

Skagerrak

Baltic Proper

Bothnian SeaGulf of Finland

Long term average water balance for the Baltic Sea as used in the POPCYCLING-Baltic model.All fluxes are given in units of km3/a.

sedimentsediment

waterwater

oGresoGsed

oGpro

oGout

oGin

oGmiw

oGmis

oGbur

POC Balance in the Aquatic Environment

oGpro primary production of POC within systemoGin import of POC from outside the systemoGout export of POC out of the systemoGmiw POC mineralisation in the water columnoGsed POC settling to the sedimentsoGres POC resuspension from sedimentsoGmis POC mineralisation in surface sedimentoGbur POC sediment burial

A particulate organic carbon mass balance was constructed for 25 aquatic systems(10 fresh water, 10 coastal and 5 open water systems) within the Baltic Sea region.

O1

O2

O3

C5

O5

281191

47.687.2

19.839.6

26.6

48.8

7.0

24.2

Index Sub-Basin riverine inflow

interbasin flow

15.0270

340

C2184

383

47.5

C1167

352

33.4

C7 251

481

11.4

170

170

O4

C6 45.3

824418

C3

100203

18.2

C454

5.9

31.0

Bothnian Bay

C8

C9

696522

12.4

4.1

O6

929393

2977

4497

NorthSea

C10

66.9152

35.4

Skagerrak

Baltic Proper

Bothnian SeaGulf of Finland

Advective fluxes of POC with river water and between basins in kt/a.

-15

-10

-5

0

5

10

15

20

1 3 5 7 9 11

North

East

South

West

TA

-15

-10

-5

0

5

10

15

20

1 3 5 7 9 11

Bothnian BayBothnian SeaGulf of FinlandNevaGulf of RigaSouthern Baltic ProperSw edish Baltic ProperDanish StraitsKattegatSkagerrak

TT

-15

-10

-5

0

5

10

15

20

1 3 5 7 9 11

Bothnian Bay

Bothnian SeaGulf of Finland

NevaGulf of Riga

Southern Baltic ProperSw edish Baltic Proper

Danish StraitsKattegat

Skagerrak

TC

-15

-10

-5

0

5

10

15

20

1 3 5 7 9 11

Bothnian Bay

Bothnian Sea

Gulf of Finland

Baltic Proper

Bottom Water

Skagerrak

TO

Seasonal temperatures in the atmospheric, terrestrial, coastal and open water units of thePOPCYCLING model in units of °C.

0

1

2

3

4

5

6

7

8

9

1 2 3 4 5 6 7 8 9 10 11 12

Bothnian Bay Bothnian Sea

Gulf of Finland NevaGulf of Riga Southern Baltic Proper

Sw edish Baltic Proper Danish StraitsKattegat Skagerrak

WST

0

1

2

3

4

5

6

7

8

9

1 2 3 4 5 6 7 8 9 10 11 12

Bothnian Bay Bothnian Sea

Gulf of Finland NevaGulf of Riga Southern Baltic Proper

Sw edish Baltic Proper Danish StraitsKattegat Skagerrak

WSC

0

1

2

3

4

5

6

7

8

9

1 2 3 4 5 6 7 8 9 10 11 12

Bothnian Bay Bothnian Sea

Gulf of Finland Baltic Proper

Skagerrak

WSO

Seasonal wind speeds over the terrestrial, coastal and open water units of thePOPCYCLING model in units of m/s.

0

200

400

600

800

1000

1200

1400

1600

1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000

conc

entr

atio

n of

-H

CH

in a

ir in

pg/

m3

estimated inflowno inflowinflow = outflowmeasured minmeasured maxmeasured mean

Concentrations in the Western Atmospheric Compartment North

East

South

West16.8

7.2

21.6

10.7

12.7 13.6

5.0 7.3

11.4

6.2

13.6 13.1

8.4

4.6

11.64.5

Atmospheric concentrations of -HCH in the western air compartment of the POPCYCLING-Baltic model.Shown are measured data from various locations in southern Scandinavia and calculated concentrationsobtained with three different boundary conditions (see text for detail). On the bottom, advectiveAtmospheric fluxes of -HCH in kt are shown for the time period 1970-2000.

a) b)

0

2

4

6

8

10

12

14

16

18

20

1980 1985 1990 1995 2000

sea

wat

er c

once

ntra

tions

of

-HC

H in

ng/

L

Bothnian BayBothnian SeaGulf of FinlandBaltic ProperBaltic BottomSkagerrakmeasured in North Seameasured in Baltic Sea

Concentrations in the Open Water Compartments

0

1

2

3

4

5

6

7

8

1980 1985 1990 1995 2000

air/o

pen

wat

er fu

gaci

ty ra

tio

SkagerrakBaltic Proper

Air Water Equilibrium in the Western Atmospheric Region

Open sea water concentrations of -HCH calculated for various water com-partments of the POPCYCLING-Balticmodel, compared to measured levels for the Baltic Sea and North Sea reported by Gaul (1992). Skagerrak and the bottom water of the Baltic Proper have lower simulated levels than the other open water compartments. In the lower graph, the calculated air-water fuga-city ratio for -HCH, indicating the equilibrium status between atmosphere and sea water, is shown for the Skagerrak and the Baltic Proper. Whereas the latter is in chemical equilibrium, net diffusive gas absorption of -HCH occurs in the former.

a) b)

0

10

20

30

40

emis

sion

s

atm

osph

ere

fore

st c

anop

y

agric

ultu

ral s

oil

fore

st s

oil

coas

tal w

ater

open

wat

er

deep

wat

er

coas

tal s

edim

ent

deep

sed

imen

t

PCB

com

posi

tion

in %

of s

um o

f 7 c

onge

ners

PCB-28PCB-52PCB-101PCB-118PCB-138PCB-153PCB-180

Average congeneric composition of the PCBs (% of sum of seven congeners) in various environmental media of the Baltic Sea environment calculated for the year 1995.

0

10

20

30

40

Bot

hnia

n B

ay

Bot

hnia

n S

ea

Gul

f of F

inla

nd

Bal

tic P

rope

r

Bal

tic P

rope

r(B

otto

m)

Ska

gerr

ak

PCB

com

posi

tion

in %

of s

um o

f 7 c

onge

ners

PCB-28

PCB-52

PCB-101

PCB-118

PCB-138

PCB-153

PCB-180

Average congeneric composition of the PCBs (% of sum of seven congeners) in various open water compartments of the Baltic Sea environment calculated for the year 1995.

0.0

0.5

1.0

1.5

2.0

2.5

fore

st c

anop

y

coas

tal w

ater

open

wat

er

coas

tal

sedi

men

t

deep

sed

imen

t

open

soi

l

fore

st s

oil

conc

entr

atio

n re

lativ

e to

Bal

tic e

nviro

nmen

t ave

rage

Bothnian Bay

Bothnian Sea

Gulf of Finland

Baltic Proper

Skagerrak

Concentrations of the sum of seven PCBs in various compartments in 1995, normalised tothe average of the concentrations in that compartment in the entire Baltic Sea environment.