Assessing the Lungs of the Ocean with the Hyperspectral PACE Mission

Abstract:

The NASA Plankton Aerosol Cloud and ocean Ecosystem (PACE) mission will explore how the ocean and atmosphere breathe through exchange of carbon dioxide and oxygen. PACE includes a hyperspectral radiometer (340 – 890 nm, 5 nm resolution, 2.5 nm steps) with bands at 940, 1038, 1250, 1378, 1615, 2130, and 2250 nm and two contributed multi-angle polarimeters. Scheduled to launch in 2023 with 1-2 day global coverage and 1 km² pixel size at nadir, the mission will provide novel insight into the interconnections between the ocean and the atmosphere to help us assess and forecast a changing world. Here, we will provide an overview of the proposed hyperspectral algorithms and advances expected from this sensor including algorithms for assessing phytoplankton dynamics, shallow aquatic habitats, floating matter, water biophysics, clouds and aerosols. Proposed new algorithms include those for phytoplankton community composition, phytoplankton pigment concentrations, net primary productivity, photosynthetically-available radiation, benthic classification, black and brown carbon aerosol concentrations, aerosol size and height, cloud droplet size, cloud top altitude, and floating matter like oil and Sargassum. Working groups within PACE are tackling how to characterize diverse phytoplankton communities, couple polarimetry and radiometry for improved atmospheric correction, evaluate and process ultraviolet signals down to 340 nm, optimize inverse modeling, tackle pixel-by-pixel uncertainty budgets, and validate products globally. The aim is to have algorithms prepared, documented and implemented at launch for new data to be incorporated into models and applications across the world.