A MUlti-scale Soil moisture-Evapotranspiration Dynamics study - AMUSED

“多尺度土壤水分-蒸散动力学研究”项目的最终目标是确定控制土壤水分和陆地-大气相互作用变化的关键主导过程的时空依赖关系。土壤水分在环境/气候系统中起着重要作用，因为陆地和陆地-大气界面的水分输送强烈依赖于一个地区的土壤水分状态。尽管它很重要，但缺乏不同空间尺度的土壤水分测量限制了我们对个体物理因素如何控制土壤水分动态的理解。鉴于最近开发用于业务数值天气和气候预测的超分辨率水文气象模式的努力，这一点尤其重要。该项目采用了新的创新技术，将宇宙射线传感器与陆地表面建模、卫星遥感、模型诊断和数据同化方法相结合，进行土壤湿度监测。新的宇宙射线传感器可以在前所未有的亚千米尺度上测量土壤湿度。这项技术彻底改变了水文气象学领域，因为它第一次提供了一个独特的机会，填补了传统的点尺度传感器和卫星遥感产品的大尺度土壤湿度观测之间的空白。这项为期3年的研究将集中在泰晤士地区附近的最初COSMOS-UK站点，该站点的人口增长、人均资源消耗的增加、土地利用的变化等复杂的相互作用可能会受到未来气候变化的影响。该项目旨在确定是否可以实现跨多个尺度的陆地-大气相互作用的统一科学，或者是否更简单的依赖于尺度的（有时是经验的）参数化与数据同化相结合可以提供独特的可接受的土壤水分动态和陆地表面过程（例如蒸散发）的预测。因此，为了确定哪些模型结构或参数化可能会通过数据同化影响状态估计，通过进一步引入模型诊断，amuse将扩展可操作数据同化实现的概念。这些发现将增强我们目前对英国数值天气预报和气候模式中土壤湿度和地表过程的理解和表征。

The ultimate goal of the "A MUlti-scale Soil moisture-Evapotranspiration Dynamics study - AMUSED" project is to identify the spatial/temporal scale-dependency of key dominant processes that control changes in soil moisture and land-atmosphere interactions. Soil moisture plays a major role in the environment/climate system because the transports of water within the land and the land-atmosphere interface are strongly dependent on the state of soil water in a region. Despite its importance, lack of soil moisture measurements at various spatial scales has limited our understanding of how individual physical factors control soil moisture dynamics. This is especially important given recent efforts develop hyper-resolution hydrometeorological models for operational numerical weather and climate predictions.AMUSED employs new innovative technology for soil moisture monitoring using cosmic-rays sensors in combination with land surface modeling, satellite remote sensing, and model diagnostics and data assimilation methods. The new cosmic-ray sensors can measure soil moisture at an unprecedented sub-kilometer scale. The technology has revolutionized the field of hydrometeorology because it provides, for the first time, a unique opportunity to fill the gap between soil moisture observations from traditional point-scale sensors and large-scale from satellite remote sensing products.The proposed 3-year research will focus on the initial COSMOS-UK sites located near the Thames region whose complex interactions of population growth, increases in per capita consumption of resources, changes in land use will likely be impacted by future climate change. The project seeks to identify whether a unified science of land-atmosphere interactions across multiple-scales can be achievable, or if simpler scale-dependent (and sometimes empirical) parameterizations in combination with data assimilation can provide uniquely acceptable predictions of soil moisture dynamics and land surface processes (e.g., evapotranspiration). AMUSED will therefore expand the notion of operational data assimilation implementation by further introducing model diagnostics in order to identify which model structures or parameterizations are likely to affect state estimation via data assimilation. These findings will enhance our current understanding and the representation of soil moisture and surface processes in numerical weather prediction and climate models in the UK.