Title: Understanding large-scale plant water relations with GRACE/GRACE-FO
Abstract: Surface and subsurface water storage (S) is an important moisture reserve for vegetation, particularly during periods of limited precipitation. It bolsters ecosystem resilience to droughts and heat waves, influences land-atmosphere exchange, and controls runoff and groundwater recharge. Yet, S is difficult to measure and observe in the field, especially at large spatial scales, and as a result, how S mediates plant-water relations is inadequately characterized. This hinders accurate simulations of many biophysical processes, such as photosynthesis, evapotranspiration, tree mortality risks, and streamflow generation.
In this seminar, I will discuss how NASA's Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) measurements of total terrestrial water storage (TWS) anomaly can fill this gap. First, I will present how I used GRACE/GRACE-FO to discover that the scientific community underestimated evapotranspiration during droughts and why. Second, I will show how I used GRACE to detect an unintended consequence of revegetation on freshwater resources in Northern China. Lastly, I will introduce an ongoing work at the University of Idaho that uses GRACE/GRACE-FO to characterize the global patterns of root zone water storage capacity and how they can improve hydrological modeling.
Bio: Meng Zhao is an Assistant Professor in the Department of Earth and Spatial Sciences at the University of Idaho. He studies the intersection between hydrology and ecology and their broader implications on climate, society, and policymaking. He employs a variety of approaches, including remote sensing (especially GRACE/GRACE-FO), GIS, Earth system modeling, and machine learning.