CO/FFCOCO/FFCO22 RATIOS DERIVED FROM RATIOS DERIVED FROM

RADIOCARBON OBSERVATIONS -RADIOCARBON OBSERVATIONS -THE ROLE OF BIOSPHERIC THE ROLE OF BIOSPHERIC

COMPONENTCOMPONENT

KAZIMIERZ ROZANSKIKAZIMIERZ ROZANSKIAGH University of Science and TechnologyAGH University of Science and Technology

Krakow, Poland Krakow, Poland

CarboEurope-IP CarboEurope-IP Annual MeetingAnnual Meeting

Poznan, 13-17.11.Poznan, 13-17.11.20020066

WP2.6 Objectives:WP2.6 Objectives:

Continue the existing Continue the existing 1414COCO22 observation network observation network

in Europe to derive the monthly meanin Europe to derive the monthly mean fossil fuel COfossil fuel CO22 component at polluted component at polluted

and background sitesand background sites

Ongoing calibration of CO as a proxy for fossil fuelOngoing calibration of CO as a proxy for fossil fuel COCO2 2 at 4 sites in Eastern and Western Europeat 4 sites in Eastern and Western Europe

(Heidelberg, Krakow, Trainou Tower and Lutjewad)(Heidelberg, Krakow, Trainou Tower and Lutjewad)

METHODOLOGY:METHODOLOGY:

BALANCE EQUATIONS:BALANCE EQUATIONS:

CCOO2mix2mix = C = COO22bgbgdd + + CCOO22bbio)io)+ + CCOO2fossil 2fossil (1)(1)

CCOO22mixmix((1414CCOO22mixmix+1000) =+1000) = CCOO22bgbgdd((1414CCOO22bgbgdd+1000)+1000)

++CCOO22bbioio((1414CCOO22bbioio+1000)+1000)

++CCOO22ffossilossil((1414CCOO22ffossilossil+1000+1000) (2)) (2)

FFCOFFCO22 = CO = CO2mix2mix[([(1414CCOO22bgbgdd - - 1414CCOO22mixmix)/()/(1414CCOO22bgbgdd + 1000)] + 1000)]

ASSUMPTIONS:ASSUMPTIONS:

(1)(1) 1414CCffossilossil = -1000 = -1000

(2)(2) 1414CCbbioio = = 1414CCbgbgd d

(3) Regional background: Jungfraujoch ((3) Regional background: Jungfraujoch (1414CCbgbgdd, CO, CObgdbgd))

BALANCE EQUATIONS:BALANCE EQUATIONS:

CCOO2mix2mix = C = COO22bgbgdd + + CCOO22bbio)io)+ + CCOO2fossil 2fossil (1)(1)

CCOO22mixmix((1414CCOO22mixmix+1000) =+1000) = CCOO22bgbgdd((1414CCOO22bgbgdd+1000)+1000)

++CCOO22bbioio((1414CCOO22bbioio+1000)+1000)

++CCOO22ffossilossil((1414CCOO22ffossilossil+1000+1000) (2)) (2)

FFCOFFCO22 = CO = CO2mix2mix[([(1414CCOO22bgbgdd - - 1414CCOO22mixmix)/()/(1414CCOO22bgbgdd + 1000)] + 1000)]

ASSUMPTIONS:ASSUMPTIONS:

(1)(1) 1414CCffossilossil = -1000 = -1000

(2)(2) 1414CCbbioio = = 1414CCbgbgd d

(3) Regional background: Jungfraujoch ((3) Regional background: Jungfraujoch (1414CCbgbgdd, CO, CObgdbgd))

I. DERIVING LOCAL FFCOI. DERIVING LOCAL FFCO22 ((CO CO 2fossil2fossil))

II. LOCAL II. LOCAL CO:CO:

CO = COCO = COmixmix - CO - CObgdbgd

III. LOCAL III. LOCAL CO/FFCOCO/FFCO22 RATIOS RATIOS

2000 2001 2002 2003 2004 2005 20060

10

20

30

40

50

60

70

80

Krakow monthly Krakow two-weekly Heidelberg

CO

/C

O2(f

oss

)

pp

b/p

pm

Monthly Monthly CO/FFCOCO/FFCO22 ratios ratios

in Krakow: 1992 – 1996 and 2000 - 2007 in Krakow: 1992 – 1996 and 2000 - 2007

77.077.05.3 (ppb/ppm)5.3 (ppb/ppm) 29.929.91.6 (ppb/ppm)1.6 (ppb/ppm)

filter

moleculardiaphragm

sievepump

CO2

flowmeter

silica gel

Radiocarbon content of soil CO2 flux ?

Is the assumptionIs the assumption 1414CCbbioio= = 1414CCbgbgdd valid ? valid ?

Monthly ”composite” samples Monthly ”composite” samples

Kraków (4)Poszyna (3)

(1,2)

a) b)

12

Three sites withThree sites withdifferent soil characteristics:different soil characteristics:

- mixed forest- mixed forest - agriculture field- agriculture field - grassland (not cultivated)- grassland (not cultivated)

Year

1998 2000 2002 2004 2006

14

C [

‰ ]

0

50

100

150

200

Schauinsland

Kraków

PZL: Mixed forest

PZO: agricultural field

PZT: grassland, not cultivated

Kasprowy W.

PZL

PZO

PZT

1960 1970 1980 1990 2000

C-1

4 in

so

il

carb

on

[p

MC

]

90

100

110

120

130

New Zealand (soil)South Carolina (soil)

North hemisphere (various soils)

2000 2001 2002 2003 2004 2005 20060

50

100

150

precip. temp.

Year

Prec

ipita

tion

[mm

]

-8-404812162024

d)

Tem

perature [oC

]

-60-40-20

020406080

100

c)

14C

[‰]

-28

-24

-20

b)

13C

PDB [

‰]

010203040506070 a)

j x[mm

ol·m

-2·h

-1]

Kraków soil Kraków atmosphere

Grassland siteGrassland site(Krakow)(Krakow)

CAB

SDB FDB

Ff (1)

Fout

Fr

FofFo

s

Ff (2)

Ff (n)

Ff

Fcw

Fin

Fs (1)

Fs (2)

Fs (n)

Fs

TERRESTRIAL BIOSPHERE

RRB

ATMOSPHERE MODEL:MODEL:

Fout(t) = Ffast(t) + Fslow(t) + Fr(t)

14Aout(t) = 1(t)14Afast(t) + 2(t)14Aslow(t) + 314Ar(t)

Year

1998 1999 2000 2001 2002 2003 2004 2005 2006

14

C [

‰ ]

0

50

100

150

200

250

Grassland

Mixed forest

Atmosphere

Year

1960 1970 1980 1990 2000

1

4C

[ ‰

]

0

100

200

300

400

500

600

At

M f

G

MODEL RESULTS:MODEL RESULTS:

MRTfast= 14 yearsMRTslow = 1500 years

Forest:

Mslow/Mfast = 40

Grassland:

Mslow/Mfast = 22

Year

1998 2000 2002 2004 2006

1

4C

[ ‰

]

0

50

100

150

200

Schauinsland

Kraków

PZL: Mixed forest

PZO: agricultural field

PZT: grassland, not cultivated

Kasprowy W.

PZL

PZO

PZT

1960 1970 1980 1990 2000

C-1

4 in

so

il

carb

on

[p

MC

]

90

100

110

120

130

New Zealand (soil)South Carolina (soil)

North hemisphere (various soils)

1414CCbbioio 1414CCmixmix

NEW ASSUMPTION:NEW ASSUMPTION:

FFCOFFCO22 = CO = CO2bgd2bgd[([(1414CCOO22bgbgdd - - 1414CCOO22mixmix)/()/(1414CCOO2mix2mix + 1000)] + 1000)]

1414CCbbioio = = 1414CCbgbgddXX

1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 20070

10

20

30

40

50

14CO2bio

= 14CO2mix

14CO2bio

= 14CO2bg

CO

2fos

sil [p

pm]

date

Differences betweenDifferences betweenFFCOFFCO2 2 estimatesestimates

No a priori assumption about 14Cbio:

FFCOFFCO22 = CO = CO2mix2mix[([(1414CCOO2bio2bio - - 1414CCOO22mixmix)/()/(1414CCOO2bio2bio + 1000)] + 1000)]

+ CO+ CO2bgd2bgd[([(1414CCOO2bgd2bgd - - 1414CCOO2bio2bio)/()/(1414CCOO2bio2bio + 1000)] + 1000)]

ForFor 1414CCOO2bio2bio= = 1414CCOO2bgd2bgd + 40 + 40

SUMMING UP:SUMMING UP:

Radiocarbon content of soil CO2 flux introduce additional uncertainty in the estimates of FFCO2 which is difficult to eliminate.

However, it turnes out that radiocarbon-based FFCO2estimates are relatively insensitive to actual radiocarbon content of the biospheric component. For the current levels of FFCO2 this additional uncertainty is in the order of 0.1- 0.5 ppm.

The modified formula for calculating FFCO2

(assumption: 14Cbio 14Cmix) opens up attractive possibilities for monitoring FFCO2 variations with relatively good precision, even without regular high-precision observations of CO2 concentations at those sites.

FFCO2 KRAKOW - 1986 - 2007