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

这一提议将解决卫星高度计、合成孔径雷达和重力对阿蒙森冰流质量不平衡的估计之间的差异，方法是利用2012/3和2013/4年度在松岛盆地的ISAR-D导线上进行的地面观测，以及2013至2016年更广泛的BAS后勤。具体来说，它将：本提案的目标是：1.在松岛盆地850公里导线沿线约10个站位的深部岩芯确定年际、年代际和~50年的平均积累。2.利用导线沿线约50个测点的浅孔，测定了近15年来近地表密度和堆积量的年际波动。3.利用地面拖曳累加雷达测量，沿导线内插累积量的空间变化，以及使用机载雷达测量，内插累积量和近地表密度的年波动。4.确定松岛盆地内部3个Nunatak站点的固体地球运动和千年尺度的冰盖抬升历史。使用年代际、波动测量和更复杂的密度模型评估堆积和密度预测模型的准确性，并使用组合来最好地估计阿蒙森海区及更远地区过去约20年的堆积和密度波动。6.使用以暴露日期为基础的西南极冰史模型，结合其他观测，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检验这一点。确定积累和密度起伏以及固体地球运动对阿蒙森扇区物质平衡的测高和重力卫星估计的贡献，并根据新的积累和测量重新评估基于搜救的物质平衡估计。这些目标直接符合ISTAR-D机会公告的目标，因为它们将导致确定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，它们响应了NERC极地战略的一个确定的优先事项--“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.