The Royal Society Discussion meeting on ‘Evolution of the Antarctic Ice Sheet: new understanding and new challenges’ took place on 17th and 18th October 2005. The aim of the meeting was to discuss both the evidence for changes in the ice sheet over the last decade and the implications of these changes for future global sea-level change. The meeting brought together scientists from a range of disciplines (including glaciology, applied mathematics, oceanography and meteorology) to present results based on satellite observation of the ice sheet; numerical modelling of its component parts, as well as the surrounding atmosphere and ocean; theoretical analysis of the stability of various components of the ice-sheet system; and direct field-based observation.
The meeting began with two presentations on the context of the ice sheet within the climate system. These talks concentrated on the glaciology of Antarctica and on the evolution of the ice sheet over the last 35 Myr. Papers by Robert Bindschadler and by David Sugden and co-authors are included in this volume.
The advent of satellite observation of the Earth in the last few decades has revolutionized our understanding of the Antarctic ice sheet. The most useful types of data available are those from the radar altimeter and synthetic-aperture radars (such as those carried on the European Space Agency's ESA 1 and 2 satellites), which can be used to measure changes in the surface elevation of the ice sheet, as well as its horizontal velocity, over huge areas and to unprecedented levels of accuracy. Progress in these fields is reviewed in papers by Eric Rignot and Duncan Wingham and co-authors in this volume. This section of the meeting documented continuing changes to the ice sheet, which the remainder of the meeting sought to explain. A series of presentations discussed evidence for meteorological and oceanographic change (the primary external forcing mechanisms of ice sheet evolution) in Antarctica over the last half century. Papers by Stan Jacobs and Andrew Monaghan and co-authors reflect the current state of knowledge in these areas.
The meeting then proceeded to consider the dynamics of the way in which the ice sheet can respond to these external changes, as well as possible sources of internally-generated variability within the ice-sheet system. Papers by Richard Hindmarsh and Geoff Evatt and co-authors are included in the volume and discuss how oceanographic change may affect the ice sheet, as well as the potential instability of subglacial lakes. The quantum leap forward in the quality and quantity of observations afforded by satellites has yet to be fully integrated into modelling studies of the ice sheet and its component parts. Three contrasting approaches to this integration are presented by Robert Athern and Richard Hindmarsh, Ian Joughin and co-authors and Andreas Vieli and co-authors. These studies illustrate how data assimilation strategies may be used to assess the state of balance of the ice sheet as a whole or to determine the controls on the flow of individual ice streams and ice shelves.
The volume concludes with an investigation by Jonathan Gregory and Philippe Huybrechts on methods of assessing the potential impacts of ice sheet change on global sea levels, and an overview of the meeting by Tony Payne and co-authors.
- © 2006 The Royal Society