14:30–14:45 | ABSTRACT 1145
EVALUATION OF HYPERSPECTRAL BACKSCATTERING RETRIEVALS ACROSS THE COASTAL AND OPEN ATLANTIC OCEAN
Recent advances in optical marine technology have enabled hyperspectral in-water measurements of aquatic particles at a fine spectral resolution continuously sampled across the entire visible spectrum. Hyperspectral particle backscattering (bbp) measurements were collected underway using a Hyper-bb system in 2024 aboard the Atlantic Meridional Transect (AMT) 31 cruise from Southampton, UK to Montevideo, Uruguay, and aboard cruises for the Connecticut Initiative on Environmental Research of Offshore Wind project. Concurrent measurements above-water hyperspectral Rrs, phytoplankton absorption, and phytoplankton pigment composition of surface waters were made. Here, we assess capabilities of hyperspectral backscatter for describing the spectral slope and shape characteristics relative to modeled assumptions used in multispectral characterizations. Across the Atlantic, observed trends in the spectral slope and magnitude of the bbp spectrum are consistent with prior relationships and modeling approaches with spectral slopes reaching 2.5 in low chlorophyll waters (n = 3434) and near 1.5 in moderate-high chlorophyll waters (n = 660). These results suggest that modeled bbp retrievals can represent general trends following simple power-law relationships. However, hyperspectral data provides additional high-frequency information that cannot be resolved with multispectral sensors. Distinct spectral features related to anomalous dispersion and residual absorption were found to be most prominent in high chlorophyll regimes. In addition, we find that backscattering efficiency (bbp/bp) is not spectrally flat in these waters, but blue-enhanced in all water types diverging from previous studies. Results from this study aim to improve approaches for characterizing the diversity of marine particles and inform bbp retrieval from hyperspectral earth observation satellites.
Xavier Warren*, University of Connecticut, [email protected], https://orcid.org/0009-0002-0828-4223
Gavin Tilstone, Plymouth Marine Laboratory, [email protected]
Thomas M. Jordan, Plymouth Marine Laboratory, [email protected]
Heidi Dierssen, University of Connecticut, [email protected]
