The Expert Group on Ice Sheet Mass Balance and Sea Level (ISMASS) aims to promote research on the estimation of the mass balance of ice sheets and its contribution to sea level, facilitate coordination among the different international efforts focused in this field; to propose directions for future research; to integrate the observations and modelling efforts, as well as the distribution and archiving of the corresponding data, and to contribute to the diffusion, to society and policy makers, of the current scientific knowledge and achievements in this field of science.
There are around 7 metres of potential sea-level rise locked up in the Greenland icesheets and 57 metres in the Antarctic icesheets.
The mass balance of a glacier or ice sheet is the net balance between the mass gained by snow deposition, and the loss of mass by melting (either at the glacier surface or under the floating ice shelves or ice tongues) and calving (production of icebergs). A negative mass balance means that a glacier is losing mass, and, for grounded glaciers and ice sheets, this mass loss directly contributes to sea level rise (the melting of floating ice shelves and ice tongues does not contribute to sea level rise, because of the lower density of ice as compared to water, which determines the floating portion of the ice). This is one of the reasons why it is important, under a warming climate, to have accurate estimates of the mass balance of glaciers and ice sheets.
The ISMASS group was formed orginally as a SCAR group, then became bipolar when cosponsored by IASC. Now it is also co-sponsored by the Climate and Cryosphere (CliC) project of WCRP.