Analyzing OA parameters in the context of the Baltic Sea

Transcription

1 Estonian Marine Institute, University of Tartu Swedish Meteorological and Hydrological Institute Analyzing OA parameters in the context of the Baltic Sea Silvie Lainela Global change in marine environment: ocean acidification and warming

2 I Ocean acidification parameters and methods II Acidification parameters analyses Collaboration between Estonian Marine Institute (EMI) and Swedish Meteorological and Hydrological Institute (SMHI) III Discussion: ocean vs the Baltic Sea

3 Cooley, S.R., Mathis, J.T., Yates, K.K. and Turley, C., Frequently asked questions about ocean acidification.

4 I ph ph = -lg [H + ] Scale: NBS vs total scale Method: - electrometric (potentiometric determination of ph) - spectrophotometric - fluorometric II Total alkalinity A T Measure of buffering capacity the ability to neutralise an addition of acid without a change in ph. Method: - e.g. open-cell potentiometric titration III Dissolved inorganic carbon - DIC Method: DIC= [CO 2* ]+ [HCO 3- ] + [CO 3 2- ] - e.g. coulometric titration IV Partial pressure of CO 2 (in air in equilibrium with sea water) Measure of the degree of saturation of the sample with CO 2. Method: - e.g. infrared CO 2 detector

5 I ph Advantage: autonomous system available Disadvantage: dependent on T, S and p II Total alkalinity A T Advantage: T and p independent Disadvantage: no autonomous system available, S dependent III Dissolved inorganic carbon - DIC Advantage: T and p independent Disadvantage: no autonomous system available, S dependent IV p(co 2 ) Advantage: autonomous system available Disadvantage: dependent on T and p Desire for high-quality measurements!

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7 Areas of expertise: Swedish Meteorological and Hydrological Institute Meteorology, hydrology, oceanography, climatology. Comes under the Ministry of the Environment and Energy. Products & services General weather forecasts and warnings, statistics, reports and expert opinions, lectures and training programmes, climate studies and research assignments Estonian Marine Institute, University of Tartu Major research topics: The biodiversity and geographical distribution of marine life in the Baltic Sea. Productivity, matter and energy cycles and population dynamics in the Baltic Sea s ecosystem. Effect of eutrophication on the marine life in the Baltic Sea.

8 I cruise: Jan Feb 2014 II cruise: July 2015 III cruise: November 2015 IV cruise: May 2016

9 Sampling and preservation 3 different samples for ph measurements Samples for TA analyses Samples for DIC analyses

10 ph Typical ph profile in the North Pacific. Clayton, T.D. and Byrne, R.H., Spectrophotometric seawater ph measurements: total hydrogen ion concentration scale calibration of m-cresol purple and at-sea results. Deep Sea Research Part I: Oceanographic Research Papers, 40(10), pp

11 ph Station: BY15, Baltic Proper Salinity range: PSU July 2015 November 2015 May 2016 Measurements done by the author.

12 TA and DIC Horizontally averaged profiles of DIC and TA (Alk) in the global oceans.. Sarmiento, J.L., Ocean biogeochemical dynamics. Princeton University Press.

13 TA and DIC Baltic Sea levels of TA and DIC: μmol kg -1 Ulfsbo, A., Kuliński, K., Anderson, L.G. and Turner, D.R., Modelling organic alkalinity in the Baltic Sea using a Humic-Pitzer approach. Marine Chemistry, 168, pp

14 Conclusion: Adjusted methods needed for region-specific acidification measurements (e.g. filtration) Environmental variations so large in the Baltic Sea the question of methods precision? Calculations / calibrations needed for lower salinities Change the focus make the coastal sea s complexity for our advantage?

15 Thank you for your attention! Silvie Lainela