第七届青年地学论坛

Input-Output method (IOM) is one of the most popular method to estimate ice sheet mass balance (MB), which has a significant advantage to present ice dynamics response to climate change. Assessing the uncertainties of MB estimation using IOM is conducive to reduce uncertainty in its future Antarctic mass budget estimate. Here, we assess the uncertainties in MB estimation due to the methodological differences in IOM, the impact of the parameterization and scale effect on the modeled surface mass balance (SMB, input), and the impact of data uncertainties of ice thickness, ice velocity and grounding line on ice discharge (D, output). We propose a method to estimate D at pixel scale for fine assessment of D’s uncertainty. Comparing with a goal of determining Antarctic MB within uncertainty of 15 Gt yr^-1, we find that different strategies in methods cause considerable uncertainty in the annual MB estimation. The significant uncertainty of modeled SMB is contributed by parameterization and scale effect. The future D’s uncertainty is mostly likely from the observational data uncertainty of ice thickness rather than that of ice velocity and grounding line. The observation precision with recent level of the three parameters all meets the goal needs. However, the data gap in ice thickness is the dominant cause of uncertainty, which, unfortunately, cannot be resolved in the near future. In addition, the annual variation of D due to the change of ice velocity and ice thickness cannot be ignored.

南极冰盖,物质平衡,通量法,表面物质平衡,冰通量