By Morgan Kelly, Princeton Environmental Institute
Birds and flowers out of sync, the integration of built and natural flood-control features, and frozen methane deep beneath the ocean are among the five projects recently funded by the Princeton Environmental Institute (PEI) as part of its Climate and Energy Challenge program. Totaling $515,000, the newly awarded research projects will run from 2018 to 2020.
Part of PEI's Grand Challenges program, the Climate and Energy Challenge addresses alternative energy and energy efficiency, challenges in climate dynamics, and the effects of climate change on Earth's ecosystems. These projects consist of faculty-led research as well as an educational component through which the project is incorporated into, or forms the basis of, undergraduate and graduate courses, senior theses and summer internships.
The most recently funded endeavors are described below.
The amount of carbon trapped in soil is nearly as large as carbon levels in the atmosphere, biosphere and surface ocean combined. This project will explore the mechanisms that govern the storage and release of soil carbon, specifically the influences of mineralogy, hydrology and temperature. It is led by Ian Bourg, assistant professor of civil and environmental engineering and the Princeton Environmental Institute; Amilcare Porporato, professor of civil and environmental engineering and the Princeton Environmental Institute; and PEI associated faculty Howard Stone, Donald R. Dixon '69 and Elizabeth W. Dixon Professor of Mechanical and Aerospace Engineering. Bourg, Porporato and Stone will examine the impact of hydrological and mineralogical variables using an idealized soil model, or a "soil on a chip." Then they will combine those data with nanoscale information of organic-carbon adsorption on mineral surfaces in order to understand transport and preservation processes at ecological scales. Their aim is to test fundamental assumptions of soil-carbon respiration in order to lay the groundwork for more accurate climate models and carbon-mitigation strategies. Four undergraduates will be working on aspects of this research in University laboratories during summer 2018.
Natural gas hydrates — ice-like water crystals containing gas molecules that are found in the microscopic pores of deep-ocean sediment — represent a vast source of natural gas as well as of the powerful greenhouse gas methane. Natural gas hydrates are stable in low ocean temperatures, but climate change could result in the uncontrolled release of this methane as ocean temperatures rise, which would further accelerate climate change. PEI associated faculty member Maurizio Chiaramonte, assistant professor of civil and environmental engineering, and Sujit Datta, assistant professor of chemical and biological engineering, will combine experiments and numerical modeling to improve existing techniques for harvesting natural gas from hydrates, while also preventing the release of methane into the atmosphere. Current recovery strategies are hindered by the limited knowledge of how the methane is transported through ocean sediment. The researchers will explore this transport mechanism through experiments on laboratory models, then test those data against numerical simulations to provide reliable predictive tools for optimizing the harvesting of natural gas hydrates.
This project led by PEI associated faculty members Ning Lin, assistant professor of civil and environmental engineering, and Guy Nordenson, professor of architecture, will bring together engineers and architects to develop nature-based strategies for enhancing flood prevention and protection for coastal regions under present and future climate conditions. The researchers will use Jamaica Bay, New York, to study how to integrate natural ecosystems — specifically wetlands — and built infrastructures to effectively protect coastal cities imperiled by rapid population growth, sea-level rise and stronger (and, possibly, more frequent) storms. The resulting framework will be expanded to other coastal regions across the nation and worldwide. The researchers will introduce a new undergraduate course, "Coastal Flood Hazards and Mitigation by Design in a Changing Climate," in which students will learn about the influence of climate change on coastal flooding, natural flood-mitigation design, and how to develop computational models of flooding and flood prevention. Two undergraduates will assist Nordenson on research and design aspects of this project during the summer.
In the tropical Indian Ocean, the natural oxygen minimum zone (OMZ), when combined with global warming and agricultural runoff, triggers coastal "dead zones" in which near-zero levels of oxygen (O2) suffocate marine ecosystems and devastate local fisheries. Laure Resplandy, assistant professor of geosciences and the Princeton Environmental Institute, will explore how natural processes precondition the Indian Ocean to very low coastal O2 levels; quantify the reinforcing role of anthropogenic activities such as river loadings; and evaluate the future risk of coastal dead zones in the region. Currently, uncertainties in the processes that create dead zones strongly limit scientists' ability to predict them and anticipate their impacts. This project will be the first to incorporate physical and biological processes at both local and global scales in order to understand and constrain the occurrence of coastal dead zones. Resplandy will combine ship- and float-based data from the Indian Ocean with a state-of-the-art global ocean model at the Geophysical Fluid Dynamics Laboratory.
Climate change appears to be initiating changes in the seasonal timing of biological events such as flower blooms that affect ecosystem function and health. PEI associated faculty Mary Caswell Stoddard, an assistant professor of ecology and evolutionary biology, will explore the impact of early flowering on the broad-tailed hummingbird to help understand how pollinator-plant interactions may be impacted by climate change. The bird's courtship and nesting cycles are becoming unsynchronized with the peak bloom of important sources of nectar as warmer temperatures and earlier snowmelt cause flowers to bloom sooner. Stoddard will use time-lapse videos and automated flower monitoring to capture the foraging behavior of individual broad-tailed hummingbirds during the breeding season. The collected data will provide a detailed picture of hummingbird foraging ecology, and they will likely reveal changes in the size and structure of the broad-tailed population due to climate-driven changes. Princeton first-year students and sophomores on the project can apply for a special two-year research fellowship at the Rocky Mountain Biological Laboratory (RMBL) in Colorado, the summer base of more than 150 biologists engaged in workshops, classes and seminars geared toward undergraduate researchers. An undergraduate student will travel with Stoddard to the RMBL in summer 2018 to observe the activity of broad-tailed hummingbirds at high-elevation field sites.