On the water circulation and chemical parameter distributions in the western and central Chukchi Sea in summer 2002 and summer 2019

Using shipborne and satellite ‒ derived data, we demonstrate the water circulation, temperature, salinity, and chemical parameter distributions in the western Chukchi Sea in the summer 2002 and summer 2019. In summer of 2002, the subsurface layer in the western Chukchi Sea was composed of Bering deep basin water with the salinity of about 33.0. In 2019, the deep layer of the western Chukchi Sea was occupied by winter Bering Sea shelf water with the salinity of 32.2–32.5. An inflow of Arctic water (increased salinity/density and low concentration of nutrients) through the Herald Canyon led to cyclonic gyre water circulation in the southwestern Chukchi Sea. The cyclonic gyre in the southwestern Chukchi Sea was characterized by anomalously low pCO₂ in the surface and subsurface layers, low pH and high pCO₂ in the bottom water, and high biomass of benthos.