The role of seasonality of organic matter (OM) production and decay in the seasonal changes of the carbonate system was studied on the basis of data received for a transect from Tromsø to Spitsbergen with a Ferrybox-equipped vessel. A 2D simplified vertical model was used for parameterization of the hydrophysical processes for a Coast–Open Arctic Transect. The biogeochemical processes were parameterized using OxyDep, a simplified biogeochemical model, that considered inorganic nutrient (NUT), dissolved organic matter (DOM), particular organic matter (POM) and biota (BIO). The carbonate system equilibrium was considered as a fast process and calculated at each time step using an iteration procedure for pH. According to the model estimates, OM production and decay play leading roles in the carbonate system seasonal dynamics. The modelled seasonal variations of pH (~0.2) are close to those observed, i.e. 7.94–7.99 in February and 8.04–8.16 in August (total scale). The surface layer pCO2 varies from 280 ppm during the OM production period to about 390 ppm in the centre of the sea and 430–460 ppm in the coastal regions in winter. The summer CO2 invasion is replaced by winter evasion. These estimates can be helpful for the planning of expedition studies and analysing the archived field data, as well as for elaborating the interannual and multidecade dynamics models.
Yakushev E. V. & Sørensen K., 2013. On seasonal changes of the carbonate system in the Barents Sea: observations and modeling. Marine Biology Research 9(9): 822-830. Article (subscription required).
