Impact of the paleo-river valleys on the chemical parameter distributions in the East Siberian Sea

Abstract

The East Siberian Sea (ESS) is the largest shelf sea of the Arctic Ocean. The paleo-river valleys of Indigirka (InV) and Kolyma (KV) Rivers are the main features of the ESS bottom topography. Using the time series of geostrophic velocities derived from satellite altimetry and ship-borne data we demonstrate the influence of InV and KV on the water circulation and chemical parameter distributions in the ESS. The KV affects the alongshore flow jet in the ESS by deflecting its inshore (southward) and jet flow accelerating. The water upwelling channeled by KV provides the nearshore area of the southern ESS with an increased concentration of nutrients and high seawater pCO2. In the InV area, the upwelling leads to stronger halocline/pycnocline and more sharp vertical gradients of the nutrients and pCO2 in the 20–30 m layer. The upwelling and water mixing in the paleovalley zones should be considered as one of the main factors leading to the high concentration of nutrients and pCO2 in the surface waters of the ESS.