Abstract:

The 3rd Chinese National Arctic Research Expedition (CHINARE 2008) was carried out from July to September in 2008. During survey, a considerable number of sea water samples were taken for CO2 parameters measurements (including total alkalinity (TA), total dissolved inorganic carbon (DIC)).The distributions of CO2 parameters in the Western Arctic Ocean were determined, and the according controlling factors were discussed. The ranges of summertime TA, nTA, DIC and nDIC in the Western Arctic Ocean surface water were 1757-2229μmol kg-1, 2383-2722μmol kg-1, 1681-2034μmol, 2119-2600μmol kg-1, respectively. As a result of dilution from ice-melt water, the surface TA and DIC concentrations were rather low. TA from the upper 100m in the south of 78°N in the Western Arctic Ocean had a good correlation with salinity, showing a conservative behavior, and the distribution followed seawater-river mixing line at salinity > 30, then followed the mixing line of seawater (diluted by river water to salinity = 30) with the ice-melt water. The distribution of DIC in the Chukchi Sea was dominated by biological production or respiration of organic matter, whereas the conservative mixing dominated the distribution of TA of mixed layer in the ice-free Canada Basin.

Key words: Dissolved inorganic carbon, total alkalinity, Western Arctic Ocean, distribution, controlling factors