Geodetic and geomorphologic data assimilation into a coupled ice sheet / solid Earth model for separating present and past ice sheet behavior in Antarctica

南极冰盖是气候系统中的关键要素，其反照率影响地表辐射平衡，主要由冰山崩解和冰下融化排放的淡水引起海平面变化，改变海洋的温盐环流，影响海冰范围，进而控制海洋向大气的热量释放。拟议的项目旨在通过模拟冰盖/固体地球耦合模型来了解冰盖的当前和过去的演变，受正在进行的冰川均衡调整的大地测量数据和冰盖几何形状的地质证据的约束。GRACE(2002年至今)、ICESat(2003年至2009年)和GPS(1995年至今)的观测结合在一起，最准确地量化了卫星时代内随时间变化的反物质平衡，并将其与数据集中的GIA贡献分开。将使用冰盖/固体地球耦合模式模拟冰盖过去的演变；将探索和应用数据同化技术，以包括对GIA的大地测量限制，以及全新世期间冰盖高度和范围的地貌证据。气候模式输出将为全新世提供改进的降水和温度强迫场，并将在同化模式运行的不确定范围内对其进行统计参数化和调整。该项目独一无二地使用了大地测量和地质数据，在现在和过去气候驱动的对立面演化之间架起了桥梁。

The Antarctic ice sheet (AntIS) is a key element in the climate system; its albedo influences the surface radiative balance, the discharge of freshwater mainly by iceberg calving and sub-glacial melting causes sea-level change, alters the ocean’s thermohaline circulation and influences the sea-ice extent, which in turn controls the heat release from the ocean to the atmosphere. The proposed project aims at understanding the current and past evolution of the AnIS with simulations of a coupled ice sheet / solid Earth model, constrained by geodetic data of the ongoing glacialisostatic adjustment (GIA) and geological evidence of the ice sheet geometry. GRACE (2002 to today), ICESat (2003 to 2009) and GPS (1995 to today) observations are combined to most accurately quantify the temporally-varying AntIS mass balance within the satellite era, and separate it from the GIA contributions in the data sets. The past evolution of the ice sheet will be simulated with a coupled ice sheet / solid Earth model; data assimilation techniques will be explored and applied allowing including geodetic constraints on GIA, as well as geomorphologic evidence of the ice sheet height and extent during the Holocene. Climate model output will provide improved forcing fields of precipitation and temperature for the Holocene, which will be statistically parameterized and adjusted within the range of uncertainties in the assimilated model runs. The project uniquely employs geodetic and geologic data to bridge between the present and past climate-driven evolutions of the AntIS.