By Kyle Turner, Charlotte Rhoads, Maria Tzortziou, Joaquim Goes, and Antonio Mannino
In early 2025, Maria Tzortziou and members of her lab at the City College of New York, Joaquim Goes from the Goes-Gomes Lab at Columbia University’s Lamont-Doherty Earth Observatory, and Antonio Mannino from NASA’s Goddard Space Flight Center, joined forces with OceanX—a global nonprofit working to unlock the ocean’s sustainable potential—to collect data in some of the most under-sampled regions of the ocean.
The primary goal of our collaboration was to support and validate science data products from NASA’s recently launched Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite mission which, as the name suggests, was designed to provide cutting-edge space-based observations to better study and monitor the processes, properties, and health of Earth’s closely interconnected ocean and atmosphere.
Changing Colors, Changing Seas
Launched in February 2024, the PACE Ocean Color instrument (OCI) is the newest, most advanced polar-orbiting satellite sensor monitoring ocean color, an essential variable for tracking long-term global climate and ecosystem change.
The PACE mission builds on a nearly 30-year continuous data record of space-based ocean color observations that have revolutionized our understanding of ocean biology and biogeochemistry, providing a daily, planet-scale view of phytoplankton—microscopic, single-celled, photosynthetic organisms that form the foundation of aquatic food webs.
Like plants on land, phytoplankton use chlorophyll and other pigments to absorb sunlight and take in carbon dioxide and nutrients to grow, producing oxygen as a byproduct. While individually microscopic, phytoplankton blooms—large proliferations of cells that can span hundreds of square kilometers or more on the ocean surface—color the water myriad hues of green, turquoise, red, or brown, depending on the type (or types) of species composing the bloom.
Compared with previous polar-orbiting ocean color sensors that could measure only a handful of colors, or wavelengths of light, PACE/OCI provides hyperspectral resolution, recording more than two hundred different wavelengths over the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. This improved “color vision” gives scientists unprecedented ability to detect different types of phytoplankton based on their unique optical signatures, which can advance our knowledge of ocean biodiversity, ecosystem dynamics, and the impacts of ongoing ocean warming and acidification, such as harmful algal blooms. This new capability to measure “all shades of color” in the ocean also allows observations of the quality and transformations of organic carbon—the fundamental building block of life on our planet.
“Ocean-truthing” satellite measure …