Julia Marrs (Fed)

Julia Marrs is a biologist in the Greenhouse Gas Measurement Program in Gaithersburg, MD. She is interested in characterizing hyperspectral field instrument systems used to remotely monitor vegetation primary productivity, and in modeling biogenic carbon dioxide fluxes.

As part of the Northeast Corridor Urban Testbed Project, she produces estimates of carbon fluxes from vegetation in urban areas throughout the Northeast US. Estimates are produced using the Vegetation Photosynthesis and Respiration (VPRM) model, which synthesizes optical and meteorological remote sensing datasets.  

Additionally, she is making field measurements of solar-induced chlorophyll fluorescence (SIF) at the Forested Optical Reference for Evaluating Sensor Technology (FOREST) and Turf for the Urban Respiration Fraction (TURF) sites, to examine controls on the relationship between SIF and biogenic carbon fluxes. She is working to quantify sources of uncertainty that can hinder accurate measurements the faint and dynamic SIF signal, with the goal of developing best practice methods for SIF instrumentation characterization and calibration traceable to SI scales.

She previously worked as a National Research Council postdoctoral research associate in the Remote Sensing Group in Gaithersburg, MD. She received her Ph.D. in Geography from Boston University, where she used tower-based SIF sensors to study leaf-level partitioning of absorbed light by plants across spatial and temporal scales.

Research Project

• FOREST

Selected publications

Jones, T.S., Logan, B.A., Reblin, J.S., Bombard, D., Ross, B., Allen, D.W., Marrs, J.K., Hutyra, L.R., 2023. “Stress-induced Changes in Photosynthesis and Proximal Fluorescence Emission of Turfgrass.” Environmental Research Communications 5: 111005. https://doi.org/10.1088/2515-7620/ad0b29

Marrs, J.K., Jones, T.S., Allen, D.W., Hutyra, L.R., 2021. Instrumentation sensitivities for tower-based solar-induced fluorescence measurements. Remote Sensing of Environment 259, 112413. https://doi.org/10.1016/j.rse.2021.112413

Marrs, J.K., Reblin, J.S., Logan, B.A., Allen, D.W., Reinmann, A.B., Bombard, D.M., Tabachnik, D., Hutyra, L.R., 2020. Solar-induced fluorescence does not track photosynthetic carbon assimilation following induced stomatal closure. Geophysical Research Letters 47, 1–11. https://doi.org/10.1029/2020GL087956

Marrs, J.K., Hutyra, L.R., Allen, D.W., 2019. Solar-induced fluorescence retrievals in the context of physiological, environmental, and hardware-based sources of uncertainty, in: Proceedings of SPIE 10986, Algorithms, Technologies, and Applications for Multispectral and Hyperspectral Imagery XXV. pp. 1–14. https://doi.org/10.1117/12.2520457

Marrs, J., Ni-Meister, W., 2019. Machine learning techniques for tree species classification using co-registered LiDAR and hyperspectral data. Remote Sensing 11, 1–18. https://doi.org/10.3390/rs11070819

Smith, I.A., Hutyra, L.R., Reinmann, A.B., Marrs, J.K., Thompson, J.R., 2018. Piecing together the fragments: elucidating edge effects on forest carbon dynamics. Frontiers in Ecology and Environment 16, 213–221. https://doi.org/10.1002/fee.1793