Satellite gravimetry and altimetry measurements record gravity and elevation changes, respectively, which are useful for determining mass and volume change of the Antarctic Ice Sheet. Common methods employ products from regional climate modeling and firn modeling to aid interpretation and to link volume changes to mass changes. Estimating deterministic parameters over defined time periods is a conventional way to evaluate those changes. To overcome limitations of deterministic analyses with respect to time-variable signals, we have developed a state-space model framework. Therein, we jointly evaluate four mass and volume data sets by coupling of temporal signal variations. We identify long-term signals of ice drainage basins that are observed by the satellite gravimetry mission GRACE and several satellite altimetry missions from April 2002 until August 2016. The degree to which we can separate long-term and short-term variations strongly depends on the similarity of the mass and volume change time series. For the drainage system of the Pine Island Glacier (West Antarctica), our results show noticeable variations of the long-term trend with an acceleration of the contribution of ice dynamics to the mass balance from −11 ± 8 to −58 ± 8 Gt a⁻¹. Our results in Dronning Maud Land (East Antarctica) show a positive long-term contribution to the mass balance at almost a constant rate. The presented approach can fit time-variable changes without artificial selection of periods of interest. Furthermore, because we only enforce common long-term time variations between mass and volume data, differences in mean trend rates help to uncover model discrepancies.

中文翻译：

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分离南极冰流域长期和短期质量变化：卫星观测和模型产品的耦合状态空间分析

卫星重力测量和高度测量分别记录重力和海拔变化，这有助于确定南极冰盖的质量和体积变化。常用方法采用区域气候建模和冷杉建模的产品来帮助解释并将体积变化与质量变化联系起来。在定义的时间段内估计确定性参数是评估这些变化的传统方法。为了克服关于时变信号的确定性分析的局限性，我们开发了一个状态空间模型框架。其中，我们通过耦合时间信号变化来联合评估四个质量和体积数据集。我们确定了 2002 年 4 月至 2016 年 8 月卫星重力测量任务 GRACE 和几次卫星测高任务观测到的冰排水盆地的长期信号。我们可以将长期和短期变化分开的程度在很大程度上取决于质量和体积变化时间序列的相似性。对于松岛冰川（西南极洲）的排水系统，我们的结果显示了长期趋势的显着变化，冰动力学对质量平衡的贡献从 -11 ± 8 到 -58 ± 8 Gt a^-1。我们在 Dronning Maud Land（东南极洲）的结果显示，对质量平衡的长期贡献几乎是恒定的。所提出的方法可以适应时变变化，而无需人工选择感兴趣的时期。此外，因为我们只强制执行质量和体积数据之间常见的长期时间变化，平均趋势率的差异有助于发现模型差异。