PacIOOS Ala Wai turbidity plume example

Have you ever wondered if you should go into the water after heavy rains? Or questioned where that brown water goes after it leaves the Ala Wai?

A team of oceanographers working with the Pacific Islands Ocean Observing System (PacIOOS) in the University of Hawaiʻi at Mānoa School of Ocean and Earth Sciences and Technology has focused their work to help address these questions and have created the PacIOOS Ala Wai Turbidity Plume Model.

Turbidity is a measure of water clarity. Tiny solids suspended in the water column can increase turbidity levels. After a significant storm event, brown water runoff from the land can raise turbidity levels in coastal waters. Brown water or storm water runoff can contain pollutants and contaminants, including sewage, harmful micro-organisms and chemicals from residential, commercial and recreational sources.

Turbidity matters, and knowing where the brown water is headed can help ocean users make more informed decisions. The new model is available at PacIOOS website.

The PacIOOS Ala Wai Turbidity Plume Model makes water quality data relevant and available to the general public in the form of a map animation. Using near real-time data of river runoff and turbidity for the Ala Wai Canal in a Regional Ocean Modeling System forecast, the map shows the possible path of brown water events leaving the Ala Wai Canal.

“The PacIOOSz Ala Wai Turbidity Plume Model can help those who recreate in the Ala Moana and Waikīkī areas make more informed decisions about when and where they choose to enter the water, especially after significant rainfall,” explains Margaret McManus, a UH Mānoa professor of oceanography. “But please remember, the plume position and turbidity values are predictions and—like a weather forecast—contain uncertainties.”

Plume model researchers include McManus, Associate Professor Brian Powell, Professor Eric De Carlo, Postdoctoral Researcher Joao Souza, PacIOOS Ocean Scientist/Web Technologist Marcia Hsu and PacIOOS Oceanographic Research Specialist Gordon Walker.