Dissolved Inorganic Carbon in Estuarine Area of the Lena River: Results of Expeditions in 2015 and 2017
During the cruises on board R/V “Akademik Mstislav Keldysh” held by SIO RAS in autumn 2015 and 2017 (63 and 69 cruises respectively) cross-sections near the estuarine area of the Lena River have been performed. Hydrochemical studies were included in scientific program of all these cruises. As one of the results, components of the carbonate system were calculated and their dynamics was studied in sea-river mixing zone. De-spite the external similarity in the distribution of hydrochemical parameters, the peculiarities of the change in the content of dissolved inorganic carbon along the river-sea mixing line in 2015 and 2017 were significantly different. In 2015, the increase in the dissolved inorganic carbon content along the river-sea mixing line was higher than can be provided by the oxidation of organic matter. In 2017, virtually all the inflow of dissolved inorganic carbon into water could be due to the destruction of dissolved or suspended organic matter. The difference in the state of the components of the carbonate equilibrium of waters and their dynamics may be because at the time of the work, the runoff of suspended matter from the Lena River in 2015 was significantly higher than in 2017.