Alekseev G.V., Smirnov A.V. , Pnyushkov A.V., Vyazilova A.E., Kulakov M.Y., Glok N.I.
In the early 1990s, there was a shift in the Arctic climate system towards warming. This shift was accompanied by water temperature and salinity changes in the Arctic Basin due to increased Atlantic water inflow, river runoff, precipitation, and ice melting. We estimated changes in the freshwater content (FWC) and freshwater inflows into the upper layer of the Arctic Basin decade by decade from the 1950s through the 2010s and showed the connection between changes in the Arctic Basin and the tropical North Atlantic. Our results show that the FWC in the upper layer of the Arctic Basin in the 1990–2000s decreased in the Eurasian Basin and increased in the Amerasian Basin. On average, the FWC increase prevailed for the whole basin due to the larger contribution of FWC changes in the Amerasian Basin that occupies 61 % of the Arctic Basin. The largest FWC for the entire Arctic Basin was observed in the 1960s and preceded the negative salinity anomaly that occurred in the North Atlantic in 1960–1970s. The reduction of the FWC in the Eurasian Basin happened due to the increased Atlantic water inflow since the 1990s that causes salinification of the upper 100 m layer despite the increased precipitation and river runoff into the Arctic Basin. A freshwater accumulation occurs in the Beaufort Gyre and the entire Amerasian part of the Arctic Basin. The FWC in the upper 0–100 m layer of the Beaufort Gyre increased in the 2000–2010s by 36 % compared to that in the 1970s. The largest FWC increase (46 %) occurred in the upper 50 m layer during this period.
