陆面模式中土壤湿度多参数化方案比较试验

土壤湿度是气候系统模式中最重要的状态变量之一。但是不同陆面模式模拟的土壤湿度存在显著差异，成为制约陆面模式发展乃至气候系统模式发展的一个瓶颈。确定陆面模式模拟土壤湿度不确定性的主要原因、识别影响土壤湿度变化的关键过程，是国际上一系列陆面多模式比较试验长期聚焦的关键科学问题。但是，由于陆地蒸散发、径流等多种过程之间存在显著的相互作用，多模式比较试验不能很好地解决该问题。近年来，多参数化方案陆面模式和申请人发展的参数化方案敏感性分析方法，成为研究这一关键科学问题新的有效工具。本项目拟使用此方法，开展全球尺度土壤湿度多参数化方案集合模拟，量化并比较多个陆面过程的参数化方案敏感性，识别影响土壤湿度变化的关键过程，阐明关键过程的空间分布格局和时间变化特征。该项目可为发展和改进陆面模式、降低土壤湿度模拟不确定性提供定量的参考依据，还能为研究全球尺度土壤湿度异常及其影响提供基础性数据。

Soil moisture is a key component of the Earth system model, but there is a remarkable disagreement in modeled soil moisture among various land surface models (LSMs). What are the major causes of the disagreements, and what processes drive the spatiotemporal variations of soil moisture? To address these questions, several international projects of LSM inter-comparisons have been initiated. However, these model inter-comparison projects failed to achieve their objectives due to the nonlinear and complex interplays between various land surface processes. Recently, multi-parameterization LSMs and parameterization sensitivity analysis emerge as promising tools to solve the problems. Here, a soil moisture multi-parameterization inter-comparison project is proposed. The project aims at quantifying the parameterization sensitivities of global-scale soil moisture simulations to several key land surface processes. By comparing the quantified parameterization sensitivities, the key land surface processes that drive the soil moisture variations at various spatiotemporal scales are expected to be revealed. The project would benefit the development of land surface models and also provide a global database of soil moisture anomalies for studying their ecological and social impacts.