University of Bergen Ingunn Skjelvan, Siv Lauvset, Truls Johannessen SA 3 Station M - Norwegian Sea pH and pCO2 time series for ocean acidification estimates University of Bergen Ingunn Skjelvan, Siv Lauvset, Truls Johannessen General Assembly 2017 Vilanova i la Geltrú, Spain; 27 – 29 June 2017

Station M 66°N 2°E in the Norwegian Atlantic Current +0.15C / S. Österhus +0.15C / 35 years

Station M www.imr.no/forskning/forskningsdata/stasjonm/view.html Deep mooring T S pH pCO2 O2 Surface buoy T S pH pCO2 (sea & air) Chl-a O2

Surface SA 3 - Station M Increasing amount of CO2 CO2 undersaturation WP 10 – Service Activities Surface Increasing amount of CO2 CO2 undersaturation Sink for atmospheric CO2 ocean uptake

Ocean Acidification Atmosphere Ocean i.e. 26% more acidic ocean Ocean WP 10 – Service Activities Atmosphere Ocean < 0,1 pH units i.e. 26% more acidic ocean Ocean CO32- (carbonate) used in skeletons and shells in marine organisms degree of CO32- saturation < 1  carbonate corrosion

Surface SA 3 - Station M Ocean Acidification … WP 10 – Service Activities Surface Ocean Acidification … -0.002 yr-1 … at a faster speed than the global mean degree of CO32- saturation -0.02 yr-1

Sub-surface SA 3 - Station M 150 m depth 200 m depth WP 10 – Service Activities Sub-surface degree of CO32- saturation degree of CO32- saturation CO32- oversaturation CO32- undersaturation 150 m depth 200 m depth