Hydrologic constraints on global carbon dioxide emissions from inland waters

内陆沃茨、溪流、河流、湖泊和水库是全球碳循环的重要组成部分，特别是作为大气中二氧化碳（CO2）的来源。尽管我们最近在内陆水域碳循环的概念方面取得了进展，但这些沃茨的全球二氧化碳排放量仍然非常不确定。这项研究将开发基于过程的计算模型的全球CO2通量从溪流，河流，湖泊和水库相结合的水流，地表水形态和碳运输和转化的模型。这些模型将为全球CO2通量和内陆水CO2源的分布以及这些通量和源如何响应径流变化提供新的见解。研究人员将培训一名博士生和一名博士后研究员，并通过尤里卡为高中女生创造教育活动，加强霍利奥克和斯普林菲尔德地区的STEM教育！与Girls，Inc.合作和马萨诸塞州阿默斯特大学。该项目的主要目标是提供来自内陆沃茨（包括河流、溪流、湖泊和水库）的全球CO2通量的可靠的、物理约束的估计。这将通过假设驱动的研究目标来实现：（1）将全球最先进的水力和水文路由系统与最近开发的CO2流网络模型相结合，包括物质传输的物理表示，输入（地下水流入、与富CO2孔隙沃茨的潜流交换、水柱呼吸）和产出（2）根据现有的全球地表和地下水地球化学观测数据集验证CO2的耦合水文和河流网络模型，并将我们基于物理的模型与现有的统计放大技术进行比较;以及（3）在一系列流动条件下应用该模型以表征CO2排放的平均和时空变化，并探索径流变化如何影响河流二氧化碳排放。该奖项将由水文科学和地球生物学与低-该奖项反映了NSF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。

Inland waters, streams, rivers, lakes, and reservoirs, act as an important component of the global carbon cycle, particularly in their role as sources of carbon dioxide (CO2) to the atmosphere. Despite recent advances in our conceptions of inland water carbon cycling, global CO2 emissions from these waters remain highly uncertain. This research will develop process-based computational models of global CO2 fluxes from streams, rivers, lakes, and reservoirs by combining models of water flow, surface water morphology, and carbon transport and transformation. The models will provide new insights into global CO2 fluxes and the distribution of inland water CO2 sources, and how these fluxes and sources respond to changes in streamflow. The researchers will train a PhD student and mentor a postdoctoral researcher, and enhance STEM education in the Holyoke and Springfield, MA area, by creating educational activities for high school girls through the Eureka! Program in collaboration with Girls, Inc. and the University of Massachusetts Amherst. The primary goal of this project is to provide robust, physically constrained estimates of global CO2 fluxes from inland waters including rivers, streams, lakes, and reservoirs. This will be accomplished through hypothesis-driven research objectives to: (1) couple global state-of-the-art hydraulic and hydrologic routing systems with a recently developed stream network model of CO2 including physical representations of mass transport, inputs (groundwater inflows, hyporheic exchange with CO2-rich pore waters, water column respiration), and outputs (primary productivity, atmospheric exchange); (2) validate the coupled hydrology and stream network model of CO2 against existing datasets of global surface and groundwater geochemical observations, and compare our physics-based model with existing statistical upscaling techniques; and (3) apply the model across a range of flow conditions to characterize average and spatiotemporal variability in CO2 emissions, and explore how changes in streamflow impact stream CO2 emissions.The award will be co-funded by the Hydrologic Sciences and the Geobiology and Low-Temperature Geochemistry programs.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.