Forecasting Milky Seas

Department of Atmospheric Science doctoral student and researcher Justin Hudson found a milky sea without relying on happenstance. He successfully predicted (or postdicted, more accurately) an occurrence of a milky sea. ScienceNews covered the research at sciencenews.org

Hudson poured over reports of milky seas from 1960 to 2023 to develop an algorithm that indicates when and where ocean conditions are ripe for milky seas. Using weather and ocean temperature data, that algorithm led him to check out satellite images from 2017 of the Indian Ocean. And there it was: a milky sea never noticed before.

Milky seas can – at first glance – look like clouds in a satellite image. However, they move quite differently than clouds do.

If you’re lucky enough to sail through a milky sea at night, the water around your ship would be glowing as far as the eye can see. In 2019 the sailing ship Ganesha was south of Java. The crew of the Ganesha happened upon a milky sea and described it as a “luminous snowfield.”Milky seas are hypothesized to be caused when ocean conditions create a natural flask with a body of water where temperature and nutrient availability allow an explosive increase of algae and the bacteria that use the algae.

Hudson estimates that milky seas occur two or three times a year, mostly in the Arabian Sea and south of Java. The research team plans to keep working toward forecasting milky seas. Hudson is a CSU doctoral student in Atmospheric Science working with Steve Miller, Director of the Cooperative Institute for Research in the Atmosphere. His presentation on this research won him the Research Top Scholar Award at the 2023 Graduate Student Showcase and an invitation to compete in CSU’s 3MT competition.