Installation of a 2-way radio antenna on the NEON tower and repeater in the instrument hut to provide better 2-way coverage across the entire University of Notre Dame Environmental Research Center (UNDERC) property.

Investigating forest dynamics, and the fine-scale phenology (either current year or previous year) that may be correlated with woody plant mortality or growth

Measure sap flow for changes over time by measuring radial and azimuthal variation in sap flow using custom built sap flow sensors.

Evaluate the performance of the Ribbit Network sensors. Comparisons of absolute and relative accuracy of CO2 concentration, temperature, humidity, and barometric pressure observations. Evaluation against NEON sensors will help us better understand how well the sensors perform in a variety of weather conditions, and learn how future work could use dense arrays of the low-cost sensors to investigate CO2 concentration heterogeneities, and potentially fluxes, in real-time.

Monitor the density and fluctuation of Earth’s ionosphere using ground-based Global Navigation Satellite System (GNSS) receivers. Specifically we want to understand how the ionosphere changes in response to auroral energy input. Certain Alaska NEON sites would be included in a larger network (25 total in Alaska, and 10 in Canada) to monitor the density and fluctuation of Earth’s ionosphere using ground-based GNSS.

Investigate how a foundation plant species (Fremont cottonwood) distributed across three major ecoregions in the southwestern U.S. responds to the synergistic impacts of climate-induced drought and temperature change, coupled with exotic species invasion

Test how the mean leaf angle, crown density, and crown rugosity co-vary and how their covariation is predictive of ecosystem functioning at tree crown, landscape, regional, and continental scales.

Examination of bioaerosol properties, flux, and vertical structure, with emphasis on thunderstorm and cold pool events.

Assess the above ground biomass burned during specific wildfires in the Western US during the 2018 fire season. This effort supports another NSF-supported project, BB-FLUX (Biomass Burning Flux Measurements of Trace Gases and Aerosols), that is focused on measuring wildfire emission fluxes.

Assess the biogeochemical controls on the decomposition of lignin versus other litter constituents in soils spanning the NEON core terrestrial sites.