陆面过程高分辨率模拟的不确定性

Uncertainties in the Regional High-Resolution Land Surface Simulations

陆地是地球气候系统的重要组成部分,是人类生产生活的重要场所。陆地表面水资源、生态系统和人类活动受到全球气候系统的影响,对气候变化响应敏感。同时,作为气候系统的下边界,陆地也深刻地影响着局地乃至全球的大气环流和气候变化。因此,准确而高分辨率的陆面过程模拟是模拟天气气候事件,进而正确认识天气气候现象的重要前提。然而,现代陆面过程模拟仍然存在很大的不确定性,主要来自于以下三个方面:模式物理过程、地表特征参数、气象驱动数据。本文总结了陆面过程高分辨率模拟,尤其是在高海拔山区模拟的不确定性来源,重点分析了降水数据的非均匀分布特征对陆面过程模拟的重要影响。提出改进陆面过程模式,提供更准确的地表特征参数分布,开展对流允许尺度的动力降尺度研究,可能是改善复杂地形条件降水模拟效果的有效途径,进而准确模拟区域水循环,实现陆面过程和区域气候模拟的最终目的。

Land is an important part of the earth’s climate system and an important place for human life. Water resources,ecosystems and human activities over land are all affected by global climate systems and are sensitively respond to climate changes. At the same time,as the lower boundary for the climate system,land exerts an important feedback on regional weather and climate system. Therefore,accurate,and high-resolution land surface simulation is an important prerequisite for simulating weather climate events and correctly understanding weather climate phenomenon. However,there is still great uncertainty in modern land surface processes simulations. The uncertainty of land surface process simulation comes from three aspects:model physical process,surface characteristic parameters,and meteorological driven data. This study summarizes the sources of uncertainty in high-resolution simulations of land surface processes,especially in high altitude mountains,focusing on the important impact of heterogeneous distribution characteristics of precipitation data on land surface process simulation. Improving land surface process model,providing realistic distribution of surface characteristic parameters,and carrying out dynamical downscaling simulation at convection permitting scale based on the high-resolution land surface statements may be an effective way to improve precipitation simulation for complex terrains. We aim to accurately simulate regional water circulation and realize the ultimate purpose of land surface process and regional climate simulation.