Shedding new light on light in the ocean

www.physicstoday.org Light drives the physics, chemistry, and biology of the ocean. Without light in the ocean, life on Earth could not exist, nor would there be fuel for the heat engine that drives the ocean’s currents and the atmosphere’s circulation. Furthermore, light and sound are the two primary means available for probing the ocean. (See the article by Tom Sanford, Kathie Kelly, and David Farmer in PHYSICS TODAY, February 2011, page 24.) Optical oceanography, which concerns all facets of light, its interactions with seawater, and its ultimate fate, is central to many important studies.1,2 It is vital for addressing problems of photosynthesis, ecosystem dynamics, the health of the ocean, seawater clarity, underwater imaging, biogeochemical cycling, carbon budgets, upper-ocean thermodynamics, and climate change. The future of the ocean and its inhabitants will depend on our ability to learn how anthropogenic activity affects them.