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

土壤湿度是气候系统中的一个重要变量。相对较少的工作已经做了组装和均匀化的土壤水分原位测量，并利用这些测量调查陆-气相互作用。该项目的研究目标是了解土壤水分如何影响美国大平原地区季节性到年际时间尺度的气候。这项工作将解决四个科学问题：（1）土地-大气相互作用，特别是与土壤水分有关的相互作用如何随空间和时间变化？(2)全球陆面模式是否准确地模拟了土壤湿度和陆-气相互作用？(3)土壤湿度在季节到年际时间尺度上影响气候的过程是什么？(4)为什么地气耦合的强度在空间和时间上有很大的变化？本研究将使用基于站点的观测为美国大平原开发土壤湿度数据库。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导出的土壤湿度算法都很重要。社区陆地模式将用于研究陆地-大气的相互作用、年际至年代际变化，并查明造成陆地-大气耦合强度时空变化的物理机制。这一项目的科学成果将支持发展更准确的气候预报，并可随时转移到其他中纬度地区。该项目更广泛的影响包括：（1）通过国家抗旱中心讲习班和联邦政府的干旱门户网站向利益攸关方传播所取得的成果（drought.gov），（2）每年向15名学生讲授以干旱科学为重点的大一研讨会，（三）建立干旱科学学习社区，鼓励跨课程学习的整合，并让学生参与面临的重大挑战之一社会，（4）培训和支持三名本科生，（5）积极参与博士生在研究的各个方面，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.