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

George Washington University, Washington DC

Investigators

Abstract

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.