2:00–12:15 | ABSTRACT 1172
PUSHING (AND USING) THE SPECTRAL FRONTIER OF OCEAN COLOUR: AQUATIC REFLECTANCE IN THE UV (350-400 NM)
Satellite “ocean colour” data in the visible range (400-700 nm) are used to measure phytoplankton and suspended sediments for global climate modelling and coastal and inland water quality management (harmful algae blooms, sediment transport). Atmospheric effects are typically removed by extrapolation from longer wavelengths (700-2500 nm), but inaccurate atmospheric “correction” remains the biggest problem in ocean colour remote sensing. Use of the 350-400 nm ultraviolet (UV) spectral range could dramatically improve atmospheric correction and hence ocean colour data quality … but is very difficult and UV bands on existing ocean colour satellites are not used operationally. The challenges of UV remote sensing of water can now be better addressed thanks to two recent game-changing developments: 1. Hyperspectral satellite data from PACE/OCI down to 350 nm; 2. Hyperspectral in situ reflectance data from HYPERNETS down to 350 nm. These datasets show a clear and plausible UV water reflectance spectrum but clearly require considerable improvement. In this study, we assess the potential of the UV (350-400 nm) for improving ocean colour remote sensing (and abovewater radiometry), review work to date and propose a new approach for atmospheric correction and new model for water reflectance in the UV.
Kevin Ruddick, RBINS, [email protected]
Quinten Vanhellemont, RBINS, [email protected]
