LAKEVIEW: NEW UNDERSTANDING OF LAKE WATER QUALITY THROUGH INTEGRATED EARTH OBSERVING SYSTEMS

Hyperspectral imagery availability is increasing with new and upcoming satellite missions such as NASA’s Plankton, Aerosol, Cloud Ocean Ecosystem (PACE) and Surface Biology and Geology (SBG) missions. Application to lakes could provide valuable insight on water quality, but there are significant challenges interpreting spectral data in terms of biogeochemical parameters and microbial community composition. The Lake^View campaign entails simultaneous airborne hyperspectral imaging and comprehensive in situ sampling of Lake Mendota in Madison, WI. With Lake^View, we address the questions: Can remotely sensed hyperspectral data provide quantitative retrievals that correlate with in situ observations? Does remotely sensed hyperspectral imagery resolve the spatial and temporal variability in water quality? Biogeochemical data from October 2023 sampling show clear spatial variability, with the two northernmost sites near the mouth of the Yahara River exhibiting the highest levels of inorganic carbon (~1.25x), total nitrogen (~2x), total phosphorus (~1.75x), and chlorophyll (~2x) across the transect. In situ optical characteristics correspond with that transect gradient. We anticipate this gradient to be evident in the microbial community and hyperspectral data currently being processed. Biweekly (weather-dependent) sampling in 2024 will capture the limnological conditions of Lake Mendota as it passes through seasonal phases that have distinct water optical characteristics. The workflow developed here is intended to inform future agency applications of hyperspectral data.

Primary Presenter: Sophia Skoglund, University of Wisconsin–Madison, Center for Limnology (skskoglund@wisc.edu)

Authors:

Sophia Skoglund, University of Wisconsin–Madison, Center for Limnology  (skskoglund@wisc.edu)

Min Oo, University of Wisconsin–Madison, Space Science and Engineering Center  (min.oo@ssec.wisc.edu)

Brendan Heberlein, University of Wisconsin–Madison, Forest and Wildlife Ecology  (bheberlein@wisc.edu)

Krystyn Kibler, University of Wisconsin–Madison, Department of Bacteriology  (kjkibler@wisc.edu)

Helen Schlimm, University of Wisconsin–Madison, Center for Limnology  (schlimm@wisc.edu)

Jimmy Sustachek, University of Wisconsin–Madison, Center for Limnology  (sustachek@wisc.edu)

Bennett McAfee, University of Wisconsin–Madison, Center for Limnology  (bmcafee@wisc.edu)

Katherine McMahon, University of Wisconsin–Madison, Department of Bacteriology  (trina.mcmahon@wisc.edu)

Philip Townsend, University of Wisconsin–Madison, Forest and Wildlife Ecology  (ptownsend@wisc.edu)

Robert Holz, University of Wisconsin–Madison, Space Science and Engineering Center  (reholz@ssec.wisc.edu)

Grace Wilkinson, University of Wisconsin–Madison, Center for Limnology  (gwilkinson@wisc.edu)

Paul Hanson, University of Wisconsin–Madison, Center for Limnology  (pchanson@wisc.edu)