NASA’s PACE and GLIMR missions will provide the first hyperspectral ocean colour-quality observations from sun-synchronous and geostationary orbits, respectively. An overview of their instrument designs, capabilities, ocean science and applications objectives, and data products will be presented. With the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission launching early in 2024, NASA will embark upon a new era of unprecedented global ocean colour and atmospheric satellite data products. PACE will be capable of performing radiometric and polarimetric ocean and atmosphere observations, returning a range of biogeophysical data from which properties of the ocean and atmosphere can be produced to add to other critical climate and Earth system variables. With advanced global remote sensing capabilities of continuous and high spectral resolution radiances from the ultraviolet to the near-infrared (320-890 nm) and multiple short-wave infrared bands, PACE’s high-quality observations will enable advanced understanding of ocean ecosystems, vulnerable coastal regions, quantification of ocean carbon cycling and phytoplankton community composition, cross-disciplinary studies of aerosol and ocean interactions, and unparalleled characterization of ecosystem change, function, and water quality.
NASA recently initiated the scientific investigation and instrument build for the Geostationary Littoral Imaging and Monitoring Radiometer (GLIMR), a hyperspectral ocean colour sensor launching after 2026 that will target the Gulf of Mexico and other coastal and ocean waters of North and South America. At the heart of the GLIMR instrument is a spectrometer with a ground sample distance of 300 m, continuous spectral range of 340 to 1040nm, and capability to scan the Gulf of Mexico in about 70 minutes. With its vantage point from geostationary orbit, GLIMR will be the first hyperspectral ocean color sensor in the Western Hemisphere to study ocean processes at the diurnal timescales required to observe the dynamic ecological, biogeochemical, and physical processes typical of coastal and ocean waters. The two main science goals of GLIMR are (1) to understand the processes contributing to rapid changes in phytoplankton growth rate and community composition, and (2) quantify how high frequency fluxes of sediments, organic matter, and other materials between and within coastal ecosystems regulate the productivity and health of coastal ecosystems. The science applications objectives aim to study the formation, magnitude, and trajectories of harmful algal blooms, oil spills, and Sargassum accumulation events.