Pacific waters in the East Siberian Sea: identification by δ13С(DIC) and [DIC]

The estimates of the scale and distribution of Bering Sea waters in the Pacific sector of the Arctic Ocean were made using the high-precision data on the isotopic composition and concentration of dissolved inorganic carbon. Despite the fact that δ¹³С(DIC) and [DIC] are not classic conservative tracers, in the East Siberian Sea, which is a zone of active interaction of river runoff with sea waters, these parameters can indicate the presence of sea waters not only of Atlantic, but also of Pacific origin, similar to the waters of the Bering Sea. Using a three-component mixing model, the spatial distribution of Pacific, Atlantic and river waters along two sections of the East Siberian Sea was estimated. The Pacific component extends from east to west to approximately 160 degrees east longitude, and possibly further west, skirting Wrangel Island not only from the north, but also possibly from the south. In the East Siberian Sea, waters similar to the open sea Bering summer surface waters are found, which are carried to the northern shelf by the circular Bering Sea Current, and upper intermediate waters, which can enter the zone of the northern shelf of the sea due to upwelling or active mixing.