Arctic Oscillation | Surface Temperatures | Stratospheric Temperatures | Clouds | Ocean

Trend in surface salinity (0-15m) for 1965-1995. Three major Russian Rivers are shown, the Lena, the Yenisey, and the Ob. Note the decrease in salinity over the White and Kara Seas, and in the near-coastal areas of the Laptev and East Siberian Seas. From M. Steele.

Freshwater trends on the Siberian Continental Shelf

There has been an increase in freshwater (decreasing salt content or salinity) in the upper ocean off the coast of Russian Siberia over the 30 year period 1965 - 1995. The decrease of salinity in the upper layers prevents mixing and increases the stratification or layering of the ocean, which prevents warmer ocean temperatures coming from the N. Atlantic from reaching the surface.

The increase in freshwater is due to a combination of increased river runoff, precipitation exceeding evaporation, ice melt, and change in ocean currents. The period of increased freshwater was also the period of increasing of the Arctic Oscillation (AO) climate index. The period started with rather low AO values, but it gradually increased over the 30 years to historically high values.

Note that the freshwater coming from the Lena River (purple and dark blue) into the East Siberian Sea stays near the coast and does not penetrate further into the central Arctic Ocean (orange).

See the Arctic Rivers section for more information on freshwater from river runoff into the Arctic Ocean.

Find more information (references and websites):

• Steele,M. and W. Ermold (2004) Salinity Trends on the East Siberian Shelves, Geophysical Research Letters, Vol. 31, L24308, doi:10.1029/2004GL021302, 2004.