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Predictive Program Helps Steer Vessel Through Ice-Choked Waters

April 27, 2020

A refined forecasting model proves its worth to the Navy.

A team of scientists and computer engineers at the Naval Research Lab has developed a forecasting program, the Global Ocean Forecast System (GOFS), to aid ships in avoiding sea ice. The program uses ocean and ice observations from several sources to create predictive maps of where icebergs were concentrated, tracking their drift and highlighting areas where they were converging or diverging. Convergence happens when icebergs ice move toward each other and become more compact, creating a risk for ships. Divergence happens when icebergs move away from each other, making it safer for ships.

The crew of the research vessel Nathaniel B. Palmer enjoy a Sunday morning sunrise as it moves into the Bellingshausen Sea. The vessel had just participated in the International Thwaites Glacier Collaboration in the Amundsen Sea region and now had to find its way to open waters.

Recently, a U.S. Antarctic Programs ship, the Nathaniel B. Palmer, while on an extended scientific mission in the Antarctic, could not maneuver around huge, stiff ice blocks while trying to reach open waters.

Palmer’s captain John-Martin Souza credits GOFS’ seven-day forecast for helping the crew negotiate the moving sea ice that constantly floats apart, then back together at different speeds and locations.

The purple dot shows the location of the ship off the coast of Antarctica. The blue arrows indicate sea ice drift in the region based on the Community Ice CodE (CICE) model in the Global Ocean Forecast System (GOFS) 3.1. Greens indicates divergence, or areas where icebergs were moving away from each other. Red indicates convergence, which icebergs were moving toward each other and becoming more compact.

“With the imagery and support products GOFS provides, I could chart a way out in only one day, after the previous four days of trying,” says Souza. “Everyone on our ship is grateful for the up-to-date information about the ice conditions.”

Initially released in 2013, the ocean forecast system has evolved to incorporate a growing number of data inputs, along with a more refined understanding of ocean and ice physics.