POSTER SESSION 4
10:30–12:30, Thursday, September 17
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1128 | POSTER 180
HYPERSPECTRAL RADIOMETRIC AND BIO-OPTICAL OBSERVATIONS FROM NORWEGIAN INLAND AND COASTAL WATERS: A FOUNDATION FOR REGIONAL ALGORITHMS, OPTICAL WATER TYPES, AND SATELLITE VALIDATION
Inland and coastal waters are increasingly affected by climate- and human-driven stressors, including warming, eutrophication, overfishing, and acidification. These pressures alter key biogeochemical and optical properties, such as chlorophyll a, total suspended matter, and the absorption of CDOM, non-algal particles, and phytoplankton. Accurate retrieval of these variables is essential for water-quality assessment and early detection of harmful algal blooms. To address this, we combine hyperspectral in situ radiometric observations with discrete water sampling for bio-optical characterization.
On-water hyperspectral measurements were acquired using the Pamela USV, equipped with a Trios skylight-blocking radiometry system to enable direct measurement of water-leaving radiance (Lw). The USV includes a remotely operated orientation system, allowing dynamic adjustment of the sensor to minimize self-shading and sun glint—an advancement over traditional above-water methods. Data collected from diverse water types were processed using a Python pipeline to derive remote sensing reflectance (Rrs, sr–1), and quality was evaluated using the QWIP scoring method. The resulting spectra span a range of water types, including phytoplankton-rich, CDOM-dominated, and cyanobacteria bloom waters.
Corresponding water samples collected at ~2 m depth were analyzed for chlorophyll a, CDOM absorption, non-algal particle absorption, and phytoplankton absorption. Bio-optical properties varied strongly among sites, with chlorophyll a reaching 44 mg m–3 under cyanobacterial bloom conditions and aCDOM(443) up to 8.44 m–1 in brown-water lakes.
This study underscores the importance of combined radiometric and bio-optical datasets for developing regional remote-sensing algorithms, identifying optical water types, and validating satellite-derived products in optically complex waters.
Vishnu Perumthuruthil Suseelan, Norwegian University of Science and Technology, [email protected], https://orcid.org/0000-0003-1439-4939
Kai Sørensen, OceanObs, [email protected]
Aria Alinejad, Norwegian University of Science and Technology, [email protected]
Joseph Landon Garrett, Norwegian University of Science and Technology, [email protected]
Tor arne Johansen, Norwegian University of Science and Technology, [email protected]
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
