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

本提案将通过利用2012/3和2013/4年松树岛盆地ISAR-D历线对地表积累、密度和固体地球运动的观测，以及2013 - 2016年更广泛的BAS物流，解决卫星高度计、SAR和重力对阿蒙森扇区冰流质量不平衡估计的差异。特别地，它将：本建议的目标是：1。确定沿横跨松岛盆地850公里的10个地点的深层岩心的年际、年代际和~ 50年的平均积累。2. 利用沿导线约50个站点的浅通道孔，确定过去~ 15年的年累积和近地表密度波动。3. 利用地面拖曳式累积雷达测量值沿横线插值累积的空间变化，利用机载雷达测量值插值累积和近地表密度的年波动。4. 在松岛盆地内部的3个月蚀点确定固体地球的运动和千年尺度的冰盖海拔历史。利用年代际、波动测量和更复杂的密度模型来评估积累和密度预测模型的准确性，并使用这些组合来最好地估计过去~ 20年来阿蒙森海及其他地区的积累和密度波动。6. 使用南极西部冰史模型，基于暴露日期，与其他观测，以最好地估计阿蒙森海区的固体地球运动，并使用地壳运动的测量来验证这一点。7 .确定积累和密度波动以及固体地球运动对测高和重力卫星估计的Amundsen扇区质量平衡的贡献，并根据新的积累和测量重新评估基于sar的质量平衡估计。最好地估计阿蒙森板块盆地的物质平衡及其随时间的变化。这些目标直接回应了ISTAR-D机会公告的目标，因为它们将导致确定该区域质量不平衡的空间和时间变异性，并除其他外，量化与卫星估计有关的不确定性。更广泛地说，它们回应了NERC极地战略确定的优先事项，“冰盖和海平面上升”，以及NERC气候和地球系统科学主题的挑战。

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.