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 their contribution to sea level, to facilitate the coordination among different international efforts focused on this field of research, to propose directions for future research, to integrate observations and modelling efforts, and promote distribution and archiving of the corresponding data, to attract a new generation of scientists into this field of research, to contribute to the diffusion of the current scientific knowledge and the main achievements to society and policymakers.

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. ISMASS was established in 1993 as a SCAR-tasked group on Antarctic mass balance and sea-level contribution, which has since become bipolar. ISMASS is international and interdisciplinary across the spectrum of relevant ice-sheet mass balance disciplines and is a self-governing expert group.

Current ISMASS chair: Heiko Goelzer

Organizational contacts are: Frank Pattyn (SCAR)Shawn Marshall (IASC), and Edward Hanna (CliC)

The Importance of Estimating Ice Sheet Mass Balance

The mass balance of an 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 the ice sheet is losing mass, and, for grounded portions of ice sheets, most of this mass loss directly contributes to sea level rise. The melting of floating ice shelves and ice tongues does not contribute much directly to sea level rise but may influence the dynamic response of the connected ice sheet inland. This is one of the reasons why it is important, under a warming climate, to have accurate estimates of the mass balance of 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 older data), the dating requires modelling the ice sheet dynamics.

For the large ice sheets of Antarctica and Greenland, the estimation of present mass balance is possible using remote sensing (satellite or airborne) techniques, though these need to be calibrated and validated against measurements done on the ice sheet 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 ice sheets. These models have to be integrated with climate models that provide the information on accumulation and melting at the glacier surface and the interaction between the ice sheets and the ocean.

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); Shawn Marshall (IASC liaison); and Edward Hanna (CliC liaison).

Membership

The ISMASS Steering Committee

  • Florence Colleoni (representing INSTANT)
  • Dan Dixon
  • Xavier Fettweis
  • Heiko Goelzer (Chair)
  • Edward Hanna (representing CliC)
  • David M. Holland
  • Shawn Marshall (representing IASC)
  • Frank Pattyn (representing SCAR)
  • Catherine Ritz
  • Andrew Shepherd

Resources

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

Publications
Links