Karol Kuli n ski Marine Chemistry and Biochemistry Department Supervisor: Janusz Pempkowiak Carbon cycling in the Baltic Sea Introduction Goal Methods Conclusion CARBOOCEAN final meeting Bergen,

Borges et al., 2006 Global uptake by the shelf seas Pg C yr -1 Global emission from estuaries, salt marshes and mangroves Pg C yr -1 (Chen & Borges, 2009) Coastal and marginal seas sink or source of CO 2 ? Introduction Goal Methods Conclusion

The Baltic Sea: - Semi-enclosed shelf sea - Sea surface: km 2 - Catchment area: km 2 - Water volume: km 3 - River run-off : 428 km 3 Baltic Sea sink or source of CO 2 ? 10.8 g C m -2 yr -1 (Thomas et al., 2003) 36.0 g C m -2 yr -1 (Kuss et al., 2006) g C m -2 yr -1 (Algesten et al., 2006) HELCOM, 2007 Introduction Goal Methods Conclusion

Baltic Sea North Sea Atmosphere Land Sediments FsFs FmFm FrFr FpFp FfFf FoFo FaFa FeFe FiFi Box model F i – input from the North Sea F e – output to the North Sea F o – precipitation F a – net CO 2 exchange with atmophere F f – fisheries F p – point sources F r – river run-off F m – return flux from sediments F s – sedimentation ∑inputs = ∑outputs F i + F e + F o + F a + F f + F p + F r + F m + F s = 0 F a = F i + F e + F o + F f + F p + F r + F m + F s Inputs – positive Outputs - negative Introduction Goal Methods Conclusion

HELCOM, 2007 Carbon input from rivers is quantified based on the national monitoring programmes data. Database : Period 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 F = C V F- carbon flux C – carbon concentration V – water volume River run-off Introduction Goal Methods Conclusion

North Sea Baltic Sea Carbon exchange between the Baltic and the North Sea x + y = 1 Sal B · x + Sal NS · y = Sal Mod x – Baltic water contribution y – North Sea water contribution Introduction Goal Methods Conclusion Hydrodynamical model CMOD Period: VI.2002 – V.2006 Time resolution: 1 hour Horizontal resolution: 2 nm Vertical resolution: 1m Parameters: Water volume Salinity Temperature F = C V F- carbon flux C – carbon concentration V – water volume

Baltic Sea DIC Thomas & Schneider, 1999 North Sea DIC Prowe et al., 2009 North Sea Baltic Sea Carbon concentrations seasonality DOC extrapolated from the weekly measurements in the near-shore zone. Introduction Goal Methods Conclusion

Algesten et al., 2006 Emeis et al., 2000 Christoffersen et al., 2007 PIG, 2005 Błaszczyszyn, 1982 Organic carbon deposition to the sediments Surface of depositional areas and the organic carbon accumulation rates are adopted from: Introduction Goal Methods Conclusion

Ullman & Aller, 1982 Carbon return flux from sediments DOC and DIC fluxes from sediments are calculated using Fick’s First Law Introduction Goal Methods Conclusion

Baltic Sea North Sea Atmosphere Land Sediments F i = 3,90 F e = -11,63 F r = 10,90 F s = -3,78 F m = 1,14 F p = 0,04 F f = -0,06 F o = 0,57 F a = -1,08 Values are in Tg C yr -1 River run-off IC: 62% OC: 38% Import from the North Sea IC: 95% OC: 5% Export to the North Sea IC: 83% OC: 17% Deposition to the sediments OC: 100% Return flux from the sediments IC: 91% OC: 9% Net CO 2 emission to the atmosphere -2.8 g C m -2 yr -1 ± 2.1 g C m -2 yr -1 Introduction Goal Methods Conclusion

Thank you

Chisholm, 2000 Anthropogenic CO 2 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) Introduction Goal Methods Conclusion