In order to investigate the effect of glacial water on the CO2 system in the fjord, we studied
the variability of the total alkalinity (AT), total dissolved inorganic carbon (CT), dissolved inorganic nutrients,
oxygen isotopic ratio (d18O), and freshwater fractions from the glacier front to the outer Tempelfjorden on
Spitsbergen in winter 2012 (January, March, and April) and 2013 (April) and summer/fall 2013 (September).
The two contrasting years clearly showed that the influence of freshwater, mixing, and haline convection
affected the chemical and physical characteristics of the fjord. The seasonal variability showed the lowest
calcium carbonate saturation state (X) and pH values in March 2012 coinciding with the highest freshwater
fractions. The highest X and pH were found in September 2013, mostly due to CO2 uptake during primary
production. Overall, we found that increased freshwater supply decreased X, pH, and AT. On the other
hand, we observed higher AT relative to salinity in the freshwater end-member in the mild and rainy winter
of 2012 (1142 lmol kg21) compared to AT in 2013 (526 lmol kg21). Observations of calcite and dolomite
crystals in the glacial ice suggested supply of carbonate-rich glacial drainage water to the fjord. This implies
that winters with a large amount of glacial drainage water partly provide a lessening of further ocean acidification,
which will also affect the air-sea CO2 exchange.
EPIC Alfred Wegener Institut