Resolving Antarctic ice mass TrEndS (RATES)

The Antarctic ice sheet is the largest on the planet by a factor 10. It holds enough ice to raise global sea level by ~65 m. Small changes in the balance between losses and gains (the mass balance) can have, therefore, profound implications for sea level, ocean circulation and our understanding of the stability of the ice mass. Local variations in mass balance may be driven by short or long term changes in ice dynamics that may or may not be related to recent climatic change. They may also be due to trends in snowfall. There is now a general consensus that the ice sheet is losing mass but the range of estimates and uncertainties are still, in most cases, larger than the signal. To solve the open question of what the time evolving mass change is, we propose combining satellite observations, climate modelling and physical constraints to solve for the independent and uncorrelated errors that have hampered previous approaches.

Sea level rise (SLR) since 1992 has averaged around 3.2 mm/yr, ~ twice the mean for the 20th Century. The cause is uncertain, but it is clear that a significant component is due to increased losses from both Greenland and Antarctica. Recent advances in regional climate modelling and analysis of gravity anomalies from the GRACE satellites have greatly improved our knowledge of both the magnitude and origin of mass losses from Greenland. Unfortunately, this is not the case for Antarctica for a range of reasons. The aim of this project is to address this shortcoming using a similar, but more comprehensive, approach to the one we used to improve our understanding of changes in Greenland. To do this, we must employ additional data and methods because i) the uncertainty in post glacial rebound for the West Antarctic Ice Sheet , in particular, is of a similar magnitude to the signal (unlike Greenland), ii) errors in observed and modelled variables are generally larger because of the paucity of in-situ data sets in, and around, Antarctica, and iii) observations in time and space are poorer for most of the ice sheet and, in particular, the areas showing the greatest change.

There are three broad categories of user groups who will benefit from the results and activities of the project in addition to scientists working directly on ice sheets and sea level rise. These are i) climate scientists, ii) the climate change policy community and iii) the general public, (including schools).

i) Climate scientists (outside of the field of research)
This community includes, for example, members of the IPCC AR5 team. We will regularly inform the coordinating lead authors for Chapter 4 (Observations: cryosphere), Chapter 5: (Information from Paleoclimate archives) and Chapter 13 (Sea Level Change) of progress and results from the project. JLB is a review editor for Ch 4 and will be attending the next author meetings in July 2011, April 2012 and Jan 2013. We are also intimately linked to the paleo sea level and GIA communities, through the PAGES programme PALSEA (http://eis.bris.ac.uk/~glyms/working_group.html) while MAK is Chair of an EU COST Action which involves leading groups in 20+ European countries working on the problem of improving models of GIA and its geodetic observation. He is also closely involved with the global POLENET community. These two networks allow him to ensure the results of the new bedrock surface velocity field are widely promoted, providing an invaluable dataset for forward and inverse modelling of GIA and constraining deglaciation history by other groups.

ii) Policy community.
We have direct links with the following organizations who have benefited from previous related research and who will benefit from this work. The list below is not meant to be exhaustive but to illustrate the type of beneficiary in this category with an indication of how they might benefit:
UK Met Office & DECC: coordinating the AVOID programme (a DECC/DEFRA funded project, http://www.avoid.uk.net/)
Public Interest Research Centre (http://www.pirc.info/) provides climate policy documents for the public and UNFCC.
Scientific Committee on Antarctic Research: coordinating role for Antarctic science.
UN Environment Programme: provides information about climate change and sea level rise to general public and educational establishments.
European Environment Agency: delivers policy information to the EC and member states.

These and other organisations will benefit from this project through gaining a clear understanding of how, and to what extent, the Antarctic ice sheet has contributed to sea level over the last two decades, the limitations in our current understanding, the implications of our findings and recommendations for future foci related to this topic. We have provide similar information to most of these organizations in the past and have good links. We will send them regular updates during the project, the final Project Report and invite them to attend the end of project workshop. Past experience indicates that this category of end user has greatly benefited from a strong interaction and involvement with the experts doing the work.

iii) The general public. Antarctic research has huge potential for capturing the public imagination and engaging students at both primary and secondary level in issues related to climate change, environmental policy, glaciology and polar processes. We know this from first hand experience. JLB and MAT currently undertake talks to local schools and will continue to do this for this project. As a RCUK Academic Fellow MAK is funded to undertake schools outreach, e.g., lecturing 6th form students at Emmanuel College, Gateshead, on sea level change. JLB was until recently head of undergraduate admissions for Geography at UoB and, in this capacity, developed a number of widening participation activities which he is still involved with.