Integrated assessment of changes in freshwater inflow to the Arctic Ocean

We present an integrated and updated quantitative estimation of the river discharge and the meltwater flux and mass contributions from glaciers to the Arctic Ocean and to sea level rise. The average meltwater fluxes from mountain glaciers and ice caps and the Greenland ice sheet have increased markedly, by 56 km3/yr water equivalent (w.e.) and 160 km3/yr w.e., respectively, from the period 1961–1992 to the period 1993–2006, reaching in total 700–800 km3/yr w.e. in 2000–2006. Terrestrial runoff is on the order of 2.4 × 103 km3/yr and remains significantly larger than the glacier meltwater flux. The terrestrial runoff increase from 1961–1992 to 1993–2006 is 87 km3/yr, which is small in relative terms, but in absolute terms it is of the same order of magnitude as the meltwater increase from glaciers. The total contribution to sea level rise from glaciers draining to the Arctic Ocean has increased from 0.27 mm/yr (1961–1992) to about 0.64 mm/yr (1993–2006). In some years of the 1993–2006 period, the glacier contribution to sea level rise reached almost 1 mm/yr.