利用多源数据研究全球海平面变化成因及冰川均衡调整信号分离

Studying global sea-level change and its causes has a crucial scientific and practical significance. Various research groups have conducted lots of research work on the physical mechanism of large-scale sea-level change and the underlying causes. However, there are still significant differences between the results, the largest controversy comes from the contribution of glacier isostatic adjustment (GIA) process and its uncertainty. This project will first compare all the contemporary glacial isostatic adjustment models and assess their uncertainty, and then we will use the combination of multiple-source sea-level change observations, including satellite altiemtry, GRACE and Argo, to extract the trend information of global sea-level change and to analyze its cause. In the last, we will develop a method to address the possibility to separate GIA and present-day mass change over ocean. This research can provide a constraint to GIA forward modeling and will benefit the community to fully understand the global sea-level change and its causes.

研究和监测全球海平面变化，分析并诠释其成因，具有至关重要的科学和现实意义。国内外研究团队对全球大尺度海平面上升的诱因及其背后的物理机制做了大量的研究工作，然而结果仍存在巨大的分歧，其中最大的争议源于对冰川均衡调整及其不确定性。本项目将对现有冰川均衡调整模型进行对比获得其不确定性；并综合利用卫星测高、GRACE重力卫星以及Argo海洋浮标等多种观测手段，对全球海平面长期变化及其诱因进行研究分析；采用三种观测数据对海洋区域冰川均衡调整信号进行分离。本项目的研究成果将为冰川均衡调整模型研制提供新约束并为完全诠释海平面变化及其成因提供依据。

海平面变化是全球气候变化的直接结果，冰川均衡调整是全球海平面变化监测研究的关键问题之一，因此全球海平面变化成因及冰川均衡调整信号的分离具有重要的科学意义。本项目对现有冰川均衡调整模型进行了细致比较，并对模型间的差异进行了量化分析；研究了冰川均衡调整过程对卫星大地测量观测的影响；对陆地和海洋间水质量的重新分布引起的海平面变化形式进行了研究；利用海平面指纹图谱法研究地表质量负荷变化对地球扁率变化影响，并对南极、格陵兰岛、阿拉斯加等地区冰川/冰盖质量损失对地球扁率的影响进行了灵敏度核检验。同时，综合利用冰川均衡调整模型、Argo、卫星测高和GRACE等卫星重力观测数据推求了两极冰盖质量变化引起的全球大尺度海平面变化特别是我国近海区域的海平面变化进行模拟分析。