Lidar for Ocean Applications

Among existing remote sensing techniques, lidar (Light Detection And Ranging, an active remote sensing technique that produces its own signal) is particularly promising for ocean applications as it can overcome some limitations of passive remote-sensed observations (Hostetler et al., 2018; Jamet et al., 2019; Behrenfeld et al., 2023). Lidar has the capability to provide vertical profiles of the particulate backscattering and seawater attenuation coefficients. A substantial additional advantage of lidar is that it operates during night-time, thus allowing for a proper exploitation of measurements carried out by polar orbiting missions during the night portion of their orbits, and monitoring latitudes up to 88° North-South. These measurement capabilities are not available from passive sensors and their availability enables profound scientific discoveries including detection of diel vertically migrating zooplankton and polar phytoplankton phenology (Behrenfeld et al., 2017, 2019). Lidar has also been used to identify atmospheric correction errors in ocean colour (Bisson et al., 2021a,b) and has been used in tandem with ocean colour to retrieve new inherent optical properties (Bisson et al., 2023). Thus, lidar systems have the potential to strongly enhance our observational capabilities for diverse atmospheric and oceanic conditions and climate scenarios and ultimately allow one to obtain a much more complete picture of a number of ocean-related scientific questions.