Prototype radar will detect areas of increased greenhouse gas emissions in the Florida Everglades
Newswise – Scientists from Atlantic University of Florida received an Exploratory Grant from the United States Department of Energy (DOE) for a prototype Ground Penetrating Radar (GPR) mounted on a small unoccupied aircraft system to effectively identify hot spots and hot moments for the build-up and release of biogenic gas in the subtropical peat soils of the Everglades of Florida. The major greenhouse gases emitted by the Everglades include carbon monoxide, methane, and nitrous oxide, which are affected by nutrients as well as hydrologic conditions.
The two-year, $ 111,655 project involves a unique multidisciplinary team from the FAU and the US Geological Survey (USGS) in collaboration with the Laboratory of Molecular Sciences of the Environment of the DOE (EMSL), a biological science facility at the Pacific Northwest Laboratory and a researcher from the United Kingdom University of Exeter. The research team will explore how certain physical properties such as soil structure and biochemical properties such as the metabolic pathway can influence the dynamics of biogenic gases.
“Peat soils are great natural producers of biogenic greenhouse gases like methane and carbon dioxide which accumulate in the soil matrix and then be released into the atmosphere,” said Xavier Comas, Ph.D., Principal Investigator and Professor, Department of Geosciences, FAU Charles E. Schmidt College of Science. âAlthough remarkable progress has been made in predicting these carbon fluxes at various spatial and temporal scales in peat soils over the past decades, there are still many uncertainties regarding the spatial distribution of hotspots for the build-up of biogenic gas and hot moments for the rapid release of biogenic gases, which this prototype drone-GPR can help us identify more effectively.
Scientists know very little about the atmospheric exchange of greenhouse gases in forested subtropical wetlands, as imagery and identification of these areas is difficult. Most current methods require soil disturbance and can generally only characterize isolated local conditions that may not be representative of heterogeneous conditions in peat soils, or have sample volumes (i.e. geochemical activity.
Airborne datasets will be monitored with ground GPR, moisture probes, gas traps equipped with time-lapse cameras, and soil measurements along the cores (i.e. porosity, hydraulic conductivity ). The GPR will allow non-invasive scaling of traditional ground measurements over larger areas without being limited by terrain roughness.
For the project, scientists will use stable C-isotope measurements of gas samples to further restrict the inferred production and release rates of GPR and to test for the presence of spatially variable dominant methanogenic pathways. They will also use X-ray computed tomography measurements via EMSL to further test the role of physical structure in the accumulation and release of biogenic gases.
The research will result in the development of preliminary remote sensing models (using gas dynamics inferred from GPR datasets) that account for the presence of hot spots and hot moments and other larger-scale predictions to ultimately generate large-scale carbon flux maps (kilometers) that could be integrated into regional models.
“We predict that an airborne GPR system could be used successfully to identify the relative dielectric permittivity contrasts associated with varying biogenic gas content in soil,” said Comas. âAs such, we believe that the physical structure of organic soil primarily dictates the distribution of hot spots and helps predict hot times for gas release triggered by changes in certain environmental factors such as atmospheric pressure or rise in the water table. ”
The project will train a graduate student and an undergraduate student. The results and products will be made available through the ESS-DIVE data repository of the DOE.
The project co-researchers are Caiyun Zhang, Ph.D., professor in the Department of Geosciences at FAU; Neil Terry, Ph.D., a research hydrologist at USGS; and Angela Gallego-Sala, Ph.D., professor of ecosystems and biogeochemical cycles and collaborator at the University of Exeter.
This project is made possible through a partnership with Guideline GEO (ABEM-Mala), the world’s leading provider of ground penetrating radar (GPR) solutions.