Ocean colour gives scientists a wider view of marine ecosystems

The colour of the sea carries information about life near its surface. Satellite instruments measure reflected light to help scientists investigate phytoplankton, the microscopic organisms that support marine food webs and participate in the movement of carbon through the ocean.

NASA's PACE mission, launched in 2024, was designed to make these observations in greater spectral detail. Looking across many wavelengths can reveal differences that are difficult to separate in a conventional colour image. The mission also observes atmospheric particles and clouds, which interact with the climate system.

Interpreting an ocean signal requires more than pointing a sensor at water. Light travels through the atmosphere, and particles above the sea affect what reaches an orbiting instrument. Measurements from ships and other platforms help researchers check their calculations against conditions at the surface.

The resulting records can support studies of changing ecosystems and the connections between ocean biology and climate. They are not a substitute for local water sampling. Their particular strength is scale: repeated views across broad regions can place a coastal observation within a much larger environmental pattern.