ISMASS (ice sheets)

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.

The ISMASS website is maintained by CliC – visit the website.

About

The Expert Group on Ice Sheet Mass Balance and Sea Level (ISMASS) is co-sponsored by SCAR, the International Arctic Science Committee (IASC), and the WCRP Climate and Cryosphere Project. The goals of ISMASS are to promote the research on the estimation of the mass balance of ice sheets and its contribution to sea level, to facilitate the coordination among the different international efforts focused on this field of research, to propose directions for future research in this area, to integrate the observations and modelling efforts, as well as the distribution and archiving of the corresponding data, to attract a new generation of scientists into this field of research, and to contribute to the diffusion, to society and policy makers, of the current scientific knowledge and the main achievements in this field of science.

Current ISMASS chair: Heiko Goelzer

Organizational contacts are: Frank Pattyn (SCAR)Gudfinna (Tolly) Adalgeirsdottir (IASC), and Edward Hanna (CliC)

Why measure the mass balance of the icesheets?

There is 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.

How is the mass balance estimated?

Past mass balance rates can be estimated from ice core data, although the proper dating of the samples is challenging. For the deeper parts of the ice core (representing the older data), the dating requires modelling the ice sheet dynamics.

For the large ice sheets of Antarctica and Greenland, the estimate of present mass balance is only possible using remote sensing (satellite or airborne) techniques, though these need to be calibrated and validated against measurements done on the glacier surface.

For predicting future mass balance, under different scenarios of climate change, it is necessary to use models of the dynamics and thermal regime of the glaciers and ice sheets. These models have to be integrated with climate models (that provide the information on accumulation and melting at the glacier surface) and oceanic models (which provide the interaction between the ice sheets and the ocean).

The Expert Group on Ice Sheet Mass Balance and Sea Level (ISMASS) is co-sponsored by SCAR, the International Arctic Science Committee (IASC) and the Climate and Cryosphere Project of WCRP.

The goals of ISMASS are to promote the research on the estimation of the mass balance of ice sheets and its contribution to sea level, to facilitate the coordination among the different international efforts focused on this field of research, to propose directions for future research in this area, to integrate the observations and modelling efforts, as well as the distribution and archiving of the corresponding data, to attract a new generation of scientists into this field of research, and to contribute to the diffusion, to society and policy makers, of the current scientific knowledge and the main achievements in this field of science.

For further details visit the ISMASS website.

Terms of Reference

News and Updates from the ISMASS Community.

Members

Contact

The contacts for the SCAR/IASC/CliC ISMASS group are: Heiko Goelzer (Chair); Frank Pattyn (SCAR liaison); Tolly Aðalgeirsdóttir (IASC liaison); and Edward Hanna (CliC liaison).

Membership

The ISMASS Steering Committee

  • Guðfinna (Tolly) Aðalgeirsdóttir (representing IASC)
  • Nancy Bertler (representing AntClimNow)
  • Florence Colleoni (representing INSTANT)
  • Dan Dixon
  • Xavier Fettweis
  • Heiko Goelzer (Chair)
  • Edward Hanna (representing CliC)
  • David M. Holland
  • Frank Pattyn (representing SCAR)
  • Catherine Ritz
  • Andrew Shepherd
  • Pippa L. Whitehouse

Resources

Publications, Data and Links of interest to the Ice Sheet Mass Balance and Sea Level community

Publications
Links