Ice export from the Laptev and East Siberian Sea derived from 18O values

Ice export from the vast Arctic Siberian shelf is calculated using dO values and salinity data for water samples collected during the International Siberian Shelf Study between August and September 2008 (ISSS-08). The samples represent a wide range of salinities and dO values due to river water inputs and sea ice removal. We estimate the fraction of water that has been removed as ice by interpreting observed dO values and salinities as a result of mixing between river water and sea water end-members as well as to fractional ice removal. This method does not assume an ice end-member of fixed composition, which is especially important when applied on samples with large differences in salinity. The results show that there is net transport of ice from both the Laptev and the Eastern Siberian Seas, and in total 3000 km of sea ice is exported from the shelf. The annual total export of ice from the entire region, calculated from the residence time of water on the shelf, is estimated to be 860 km yr. Thus, changes in ice production on the shelf may have great impact on sea ice export from the Arctic Ocean.