ISTAR-D - The contribution to sea-level rise of the Amundsen Sea sector of Antarctica

This proposal will resolve the differences between satellite altimeter, SAR and gravity estimates of the mass imbalance of the Amundsen sector ice streams, through exploiting surface observations of accumulation, density and solid Earth motion made on the ISAR-D traverses in 2012/3 and 2013/4 of the Pine Island basin, and the wider BAS logistics from 2013 to 2016. In particular, it will:The objectives of this proposal are:

1. Determine, at deep cores at some 10 sites along an 850 km traverse throughout the Pine Island Basin, the inter-annual, decadal, and ~ 50 year average accumulation.
2. Determine, using shallow access holes at some 50 sites along the traverse, the annual fluctuations of accumulation and near surface density over the past ~ 15 years.
3. Interpolate along the traverse the spatial variation in accumulation using surface-dragged accumulation radar measurements, and the annual fluctuations of accumulation and near surface density, using airborne radar measurements.
4. Determine the motion of the solid Earth, and millennial-scale ice sheet elevation history, at 3 nunatak sites in the interior of the Pine Island Basin.
5. Evaluate the accuracy of accumulation and densification forecast models using the inter-decadal, fluctuation measurements, and more sophisticated densification models, and use the combination to best estimate the fluctuations of accumulation and density over the past ~ 20 years in the Amundsen Sea sector and beyond.
6. Use a West Antarctic ice history model, based on exposure dates, with other observations, to best estimate the solid Earth motion of the Amundsen sea-sector, and use the measurements of crustal motion to test this.
7. Determine the contributions of accumulation and density fluctuations, and solid Earth motion, to altimetric and gravity satellite estimates of the mass balance of the Amundsen sector, and reassess the SAR-based estimates of mass balance in the light of the new accumulation and measurements.
8. Best estimate the mass balance, and its change in time, of the Amundsen sector basins.

These objectives answer directly to the objectives of the ISTAR-D Announcement of Opportunity, in that they will result in the determination of the spatial and temporal variability of the regions mass imbalance, and, inter alia, quantify the uncertainties associated with the satellite estimates. More widely, they answer to an identified priority of the NERC Polar Strategy, "Ice sheets and Sea Level Rise", and to challenges of the NERC Climate and Earth System Science themes.

This proposal (ISTAR-D) is aimed at determining the recent past, and present contribution to sea level of the Amundsen sector drainage basins. It will run along side the second activity of this NERC opportunity, ISTAR-C, that will focus on the dynamical behaviour of the sector's ice streams. Together, the two activities will provide the best knowledge, and prediction of this sector's contribution to sea level. We intend to pursue a common impact plan with ISTAR-C, as our contribution to the wider impact plan of the ISTAR program as a whole. The following groups are identified as key stakeholders in iSTAR-C/D science, and will be specifically targeted by our Knowledge Exchange activities:

1. Intergovernmental Panel on Climate Change (IPCC). The IPCC is by far the most authoritative group synthesising scientific knowledge and predictions of sea-level rise. It is therefore essential that l group synthesising and delivering sea-level rise projections to policy-makers, it is essential that iSTAR-C/D science is delivered to IPCC. Science to be included in the IPCC 5th Assessment Report has to be submitted for peer review by July, 2012, iSTAR-C/D science will only be available to subsequent reports. Since IPCC reports relies almost exclusively on peer-reivewed literature, delivery to IPCC must be achieved through such publications. PI ISTAR-C is a Coordinating Lead Author for IPCC 4th and 5th Assessment Report, and can direct ISTAR-C and -D investigators to ensure ISTAR C and D fully contribute to the IPCC.
2. UK Environment Agency. Because of limitations of the IPCC sea-level rise projections, the UK Environment Agency have found the need to develop its own UK specific sea-level rise scenarios. These were developed in conjunction with the Hadley Centre and BAS. A regular dialogue with the key Programme Managers at the Environment Agency (e.g. TE2100) will ensure that the Environment Agency is fully able to use science outcomes.
3. Living With Environmental Change (LWEC). LWEC is a UK government initiative to optimize the coherence and effectiveness of UK environmental research funding and ensure government, business and society have the foresight, knowledge and tools to mitigate, adapt to and capitalise on environmental change. The ISTAR-C PI currently leads an Accredited Activity ("Ice sheets and sea-level rise") within the Living With Environment Change programme (LWEC). Early discussions, indicate that the activities described in iSTAR-C/D are welcome as a substantial addition to this activity. LWEC is proving to be an effective method of delivery to UK government departments and iSTAR-C/D will be well-positioned to contribute, especially to the activities such as LWEC's development of the UK First Flood Research Strategy .
4. Space and Meteorological Operational Agencies & Supply Industry. The CryoSat-2 radar design, that originated with the ISTAR-D PI, has been adopted as standard for future European operational meteorological and oceanographic satellites, and in particular the GMES Sentinel 3 and NOAA/Eumetsat/CNES Jason-CS missions. ISTAR-D will provide the proving ground for the scientific data processing of these data. The ISTAR-D PI is actively involved in the provision, with industry, of ground processing software for these missions.