CAREER: Observation-Driven Mapping of the Linkages between the Terrestrial Water, Energy and Carbon Cycles

陆地、生物圈和大气之间的水、能量和碳交换在地球气候中起着关键作用。水、能源和碳循环的陆地或陆地组成部分紧密相连，并以协调的方式运作。例如，大气中二氧化碳的增加改变了植被生物量的数量，从而改变了生态系统的光合作用和蒸腾（从而改变了热交换）率。用于水文、生态和气候模式的陆地表面模式需要准确地表示陆地循环之间的联系。由于缺乏对能够量化这些联系的关键变量的直接观察，这些模式的预测结果不确定。该项目利用地表土壤湿度、土壤温度和植被指数的卫星测量信息，采用一种新的观测驱动方法来诊断和绘制区域尺度上的联系。绘制不同季节、生态和环境条件之间的联系，有助于了解陆地水、能源和碳循环如何在现实世界中相互联系和运作。该CAREER提案的教育目标是提高华盛顿特区研究生、本科生和6-12年级预科学生的环境知识，促进科学发现。这项教育工作包括让当地学校的少数民族学生参与STEM领域，重点是气候和陆地-大气相互作用。本研究解决了目前在理解陆地-大气相互作用/耦合时空变化方面的知识空白。研究计划包括：(i)基于变分方法开发一个最先进的框架，根据陆地表面状态观测中包含的隐含信息，在一系列时空尺度上诊断和绘制陆地水、能源和碳循环之间的联系；（ii）在点尺度（现场，合成模拟）和大尺度（美国大陆）上测试方法（iii）并通过绘制和研究不同生物群落，回波水文区域，季节和环境条件之间的联系来扩展我们对陆地循环之间耦合的基本理解。这些周期之间的联系的观测驱动形式可用于指导改进陆地表面/地球系统模式的预测能力，从而改进对区域陆地表面通量、气候和气候预估的模拟。本提案中开发的研究方法和低阶逆建模技术引起了广泛的兴趣，包括物理学家、应用数学家、气象学家、气候科学家和水文学家。该教育计划利用GLOBE（全球学习和观察以造福环境）框架，让来自华盛顿都会区的6-12名学生参与STEM，让他们参与活动，提高他们对陆地大气相互作用的理解。我们将通过开发一个由参与教师、在线资源和项目评估和评估工具组成的网络，确保该项目的长期可持续性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The exchange of water, energy, and carbon between the land, biosphere and atmosphere play a key role in the Earth’s climate. The terrestrial or land component of water, energy and carbon cycles are strongly linked and operate in a harmonized manner. For example, an increase in atmospheric carbon dioxide modifies the amount of vegetation biomass, thus altering ecosystem photosynthesis and transpiration (hence, heat exchange) rates. Land Surface Models used in hydrologic, ecological and climate models require accurate representation of the links between terrestrial cycles. The lack of direct observation of key variables that can quantify these linkages result in uncertain projections from these models. Using satellite information on land surface state measurements of soil moisture, soil temperature and vegetation index, this project applies a novel observation-driven approach to diagnose and map the linkages at regional scale. Mapping the linkages across different seasons, ecological and environmental conditions advances understanding of how the terrestrial water, energy and carbon cycles are linked and operate in the real world. The educational goal of this CAREER proposal is to enhance environmental knowledge and promote scientific discovery on the part of graduate, undergraduate and 6-12th precollege students in the Washington DC area. This education effort includes engaging minority students from local schools in STEM fields with a focus on climate and land-atmosphere interaction. This research addresses the current knowledge gap in understanding the spatio-temporal variations of land-atmosphere interactions/couplings. The research plan includes (i) developing a state of the art framework based on a variational methodology to diagnose and map the linkages between the terrestrial water, energy and carbon cycles across a range of temporal and spatial scales from the implicit information contained in land surface state observations; (ii) testing the methodology at point scale (field site, synthetic simulations) and at large scale (Continental US) (iii) and expanding our fundamental understanding of the coupling between the terrestrial cycles by mapping and studying the linkages across different biomes, echo hydrological regions, seasons and environmental conditions. The observation-driven form of the linkages between the cycles can be used to guide improvements in the predictive capabilities of Land Surface/Earth System models and hence improve simulation of regional land surface fluxes, climate and climate projections. The research method and the low order inverse modeling techniques developed in this proposal is of interest to a broad community, including physicists, applied mathematicians, meteorologists, climate scientists and hydrologists. The educational plan leverages the GLOBE (Global Learning and Observations to Benefit the Environment) framework to engage 6-12 students from the DC metro area in STEM by engaging them in activities that will enhance their understanding of land atmosphere interaction. We will ensure long-term sustainability of this program by developing a network of participating teachers, online resources, and program assessment and evaluation tools.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.