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Bergen mesocosm experiment 2011. Gisle Nondal , Richard Bellerby , Anna Silyakova , Helene Frigstad and Emanuele Reggiani. London 29.09.11. Raunefjorden , Norway. 9 mesocoms deployed and moored e ach 25 m long with a volume of ca. 75 m 3 I nitially open at top and bottom
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Bergen mesocosmexperiment 2011 Gisle Nondal, Richard Bellerby, Anna Silyakova, Helene Frigstad and Emanuele Reggiani London 29.09.11
9 mesocomsdeployedandmoored • each 25 m longwith a volumeof ca. 75 m3 • Initially open at top andbottom • coveredbynetswith 3 mm meshsize • enclosedwaterexchangingfor 3 days (Courtesy of Ulf Riebesell, IFM-GEOMAR)
Set-up 3 mesocosms moored in a row With anchor weights at each end set of 3 mesocosms anchor weights (old railway wheels) (Courtesy of Ulf Riebesell, IFM-GEOMAR)
CO2 Enrichment Target fCO2 1 2 3 4 5 6 7 8 9 180 280 390 560 840 1120 1400 2000 3000 µatm glacial pre- present 2x p.i. 3x p.i. 4x p.i. 5x p.i. industrial
After 3 days: • Closingsediment traps • Pullingupupperbags • Addingsalt (volumedetermination) • Homogenizing • CO2enrichment (in 4 steps) • Nutrientaddition (once) (Courtesy of Ulf Riebesell, IFM-GEOMAR)
Sampling procedure: Sampling at the Mesocoms with zodiacs
Integrating water sampler Gas samples directly taken on “Wassermann”
Carbonate chemistry • In situ measurements of: • Total inorganic carbon (DIC) DIC= [CO2(aq)]+[H2CO3]+[HCO3-]+[CO32-] • Total alkalinity At=[HCO3-] +2[CO32-]+[B(OH)4-]+ [OH-]+[HPO42]+2[PO43]+ [SiO(OH)3-]+ [HS-]+[NH3]-[H+]-[HSO4-]-[HF]-[H3PO4] • pH pH = -log[H+] Overdetermination!!