CAREER: Drought Predictability and the Role of Land-Atmosphere Interactions in the U.S. Great Plains

土壤水分是气候系统中的一个重要变量。在收集和均化土壤湿度的现场测量并利用这些测量来研究陆地-大气相互作用方面所做的工作相对较少。该项目的研究目标是了解土壤湿度如何影响美国大平原季节和年际时间尺度上的气候。这项工作将解决四个科学问题：(1)陆地-大气相互作用，特别是与土壤湿度有关的陆地-大气相互作用如何在空间和时间上变化？(2)全球陆地表面模式是否准确地模拟了土壤水分和陆地-大气相互作用？(3)土壤水分在季节和年际时间尺度上通过什么过程影响气候？(4)为什么陆地-大气耦合的强度在时空上有很大的变化？本研究将利用基于站的观测为美国大平原开发一个土壤水分数据库。这些数据对于开发气候预报工具、校准陆面模型和验证卫星土壤湿度算法非常重要。共同体陆地模式(CLM)将用于调查陆地-大气相互作用、年际到年代际变化，并查明造成陆地-大气耦合强度时空变化的物理机制。该项目的科学成果将支持制定更准确的气候预报，并可很容易地转移到其他中纬度地区。该项目的广泛影响包括(1)通过国家抗旱中心研讨会和联邦政府干旱门户网站(drought.gov)向利益攸关方传播所获得的成果，(2)向15名学生/年教授以干旱科学为重点的新生研讨会(FYS)，(3)建立干旱科学学习社区，以鼓励跨课程学习的整合，并让学生参与社会面临的重大挑战之一，(4)培训和支持三名本科生，以及(5)让一名博士生积极参与研究的各个方面，包括指导本科生。

Soil moisture is an important variable in the climate system. Relatively little work has been done to assemble and homogenize in situ measurements of soil moisture and to utilize these measurements for investigating land-atmosphere interactions. The research goal of this project is to understand how soil moisture influences climate on seasonal to interannual timescales in the U.S. Great Plains. This work will address four scientific questions: (1) How do land-atmosphere interactions, specifically those related to soil moisture, vary over space and time? (2) Are soil moisture and land-atmosphere interactions accurately simulated in global land surface models? (3) What are the processes through which soil moisture influences climate on seasonal to interannual time scales? (4) Why are there substantial spatial and temporal variations in the strength of land-atmosphere coupling?This study will develop a soil moisture database for the U.S. Great Plains using station-based observations. These data are important for developing climate forecasting tools, calibrating land surface models, and validating satellite-derived soil moisture algorithms. The Community Land Model (CLM) will be used to investigate land-atmosphere interactions, interannual to interdecadal variability and to identify the physical mechanisms that are responsible for spatial and temporal variations in the strength of land-atmosphere coupling. The scientific outcomes of this project will support the development of more accurate climate forecasts and is readily transferable to other mid-latitude regions. Broader impacts of this project include (1) disseminating the obtained results to stakeholders through National Drought Mitigation Center workshops and the federal government's drought portal (drought.gov), (2) teaching a Freshman Year Seminar (FYS) focused on drought science to 15 students/year, (3) establishing a Drought Science Learning Community to encourage integration of learning across courses and to involve students in one of the grand challenges facing society, (4) training and supporting three undergraduate students, and (5) involving actively a PhD student in all aspects of the research, including mentoring the undergraduate students.