The HSRL Pathfinder – a Multifunctional Lidar Mission Concept for Aerosol, Cloud, Ocean, Snow, and Sea Ice Observations

We present a cross-cutting satellite mission concept for acquiring advanced aerosol, cloud, ocean, snow, and sea ice observations with a multifunctional high-spectral-resolution lidar (HSRL). The mission would enable significant advances in studies of aerosol direct and indirect radiative effects, aerosol-cloud interaction, aerosol transport and speciation, air quality, ocean ecosystem science, ocean-atmosphere interaction, snow water equivalent, and seasonal sea ice. Our multifunctional lidar concept illustrates advanced remote sensing capabilities for potential consideration in the upcoming 2027 US Decadal Survey for Earth science. It also represents a point design for a potential technology/science demonstration mission that could be flown in conjunction with NASA’s Atmosphere Observing System – Sky mission that is planned for launch in 2030. Specifically, the HSRL Pathfinder provides HSRL and polarization capabilities at 532 nm and elastic backscatter lidar capability at 1064 nm. Implementation of this mission concept would provide valuable observations of aerosol extensive properties (aerosol extinction and backscatter), intensive properties (lidar ratio, aerosol depolarization ratio, backscatter Angstrom exponent), and aerosol type. Employment of the high-spectral-resolution-lidar technique enables accurate estimation of both the aerosol optical properties and their uncertainties, making the data useful for assimilation into models. High vertical sampling resolution (1.25 m) enables retrievals of extinction and cloud droplet number concentration in warm clouds, depth-resolved ocean optical properties (diffuse attenuation coefficient and particulate backscatter), snow depth, and seasonal sea-ice thickness.