Karol Kuli n ski Marine Chemistry and Biochemistry Department Supervisor: Janusz Pempkowiak

1. Introduction GoalMethodsConclusion Carbon cycling in the Baltic Sea Karol Kulinski Marine Chemistry and Biochemistry Department Supervisor: Janusz Pempkowiak CARBOOCEAN final meeting Bergen, 5-9.10.2009

2. IntroductionGoalMethodsConclusion Coastal and marginal seas sink or source of CO2? • Global uptake by the shelf seas 0.33-0.36 Pg C yr-1 • Global emission from estuaries, salt marshes and mangroves -0.50 Pg C yr-1 • (Chen & Borges, 2009) Borges et al., 2006

3. Introduction GoalMethodsConclusion • The Baltic Sea: • Semi-enclosed shelf sea • Sea surface: 385 000 km2 • Catchment area: 1 700 000 km2 • Water volume: 23 000 km3 • River run-off : 428 km3 • Baltic Sea sink or source of CO2? • 10.8 g C m-2 yr-1 (Thomas et al., 2003) • 36.0 g C m-2 yr-1 (Kuss et al., 2006) • -35.4 g C m-2 yr-1 (Algesten et al., 2006) HELCOM, 2007

4. Introduction GoalMethodsConclusion Box model Atmosphere Fa Fo North Sea Ff Fi BalticSea Fp Fe Fr Land Fs Fm Sediments ∑inputs = ∑outputs Fi + Fe + Fo + Fa + Ff + Fp + Fr + Fm + Fs = 0 Fa = Fi + Fe + Fo + Ff + Fp + Fr + Fm + Fs Fi – inputfromthe North Sea Fe – output to the North Sea Fo – precipitation Fa – net CO2exchangewithatmophere Ff – fisheries Fp – point sources Fr – riverrun-off Fm – return fluxfromsediments Fs – sedimentation Inputs – positive Outputs - negative

5. Introduction GoalMethodsConclusion F = C • V F- carbon flux C – carbon concentration V – water volume River run-off Carbon input from rivers is quantified based on the national monitoring programmes data. Database : Period 2003-2008 Monthly means of TOC and TIC concentrations Monthly means water volume 63 the largest rivers 85% of the total water volume from river run-off HELCOM, 2007

6. Introduction GoalMethodsConclusion CarbonexchangebetweentheBaltic and the North Sea F = C • V F- carbon flux C – carbon concentration V – water volume North Sea • Hydrodynamical model CMOD • Period: VI.2002 – V.2006 • Time resolution: 1 hour • Horizontal resolution: 2 nm • Vertical resolution: 1m Baltic Sea x + y = 1 SalB· x + SalNS· y = SalMod • Parameters: • Water volume • Salinity • Temperature x – Baltic water contribution y – North Sea water contribution

7. Introduction GoalMethodsConclusion Carbonconcentrationsseasonality DOC extrapolated from the weekly measurements in the near-shore zone. North Sea Baltic Sea DIC Thomas & Schneider, 1999 Baltic Sea North Sea DIC Prowe et al., 2009

8. Introduction GoalMethodsConclusion Organiccarbondeposition to thesediments Surface of depositional areas and the organic carbon accumulation rates are adopted from: • Algesten et al., 2006 • Emeis et al., 2000 • Christoffersen et al., 2007 • PIG, 2005 • Błaszczyszyn, 1982

9. Introduction GoalMethodsConclusion Carbon return fluxfromsediments DOC and DIC fluxes from sediments are calculated using Fick’s First Law Ullman & Aller, 1982

10. Introduction GoalMethodsConclusion River run-off IC: 62% OC: 38% Atmosphere Import fromthe North Sea IC: 95% OC: 5% Fo = 0,57 Fa = -1,08 North Sea Ff = -0,06 Fi = 3,90 Fp = 0,04 Export to the North Sea IC: 83% OC: 17% BalticSea Fe = -11,63 Fr = 10,90 Deposition to thesediments OC: 100% Land Fs = -3,78 Fm = 1,14 Valuesarein Tg C yr-1 Sediments Return fluxfromthesediments IC: 91% OC: 9% Net CO2emission to theatmosphere -2.8 g C m-2 yr-1± 2.1 g C m-2 yr-1

11. Thank you

12. IntroductionGoalMethodsConclusion Anthropogenic CO2 emission ~6.5 Pg C yr-1 50% of this is accumulated in the atmosphere ~28-30% ocean uptake ~20-22% land uptake (Emerson & Hedges, 2008; Sabine et al., 2004; Takahashi et al., 2002 & 2009) Chisholm, 2000