PAR sensors measure Photosynthetically Active Radiation, which is the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. Essentially, PAR sensors provide a measure of the amount of light available for photosynthesis and how that varies over time and depth in the water column. Chlorophyll, the most abundant plant pigment in land plants and in ocean phytoplankton, is most efficient at capturing red and blue light.
PAR instruments on the Cabled Array are installed on the Science Pods on the Shallow Profiler Moorings at Slope Base the Oregon Offshore site, and at Axial Base. PAR sensors on the Cabled Array are provided by Satlantic.