At the end of March, when Arctic sea ice hits its lowest extent for the season, scientists will turn to 40 years of satellite data to determine if 2018 is a year for the history books. Already, sea ice extent was at a record low for February, and it's been the warmest winter on record so far.
Increasingly, however, as global warming rapidly changes daily life in the Arctic, governments and scientists are placing a greater priority on using new technologies to make better predictions of seasonal sea ice, not just analyzing the past.
"We want more regional, fine-resolution information of where the sea ice might be," said Helen Wiggins, program director for the Arctic Research Consortium of the United States, which oversees the Sea Ice Prediction Network.
In January, scientists, government officials, and industry representatives from around the world met in Tromso, Norway, to discuss improving sea ice forecasting in the Arctic.
The region's waterways are increasingly open for business, with ships embarking earlier and returning later in summer, and researchers want to understand exactly how northern communities and industries use current sea ice predictions and charts to plan their operations and reduce economic and safety risks. This activity is only expected to increase in the coming years, as the European Arctic, the Northwest Passage, and some areas in the Northern Sea Route experience less and less summer sea ice.
Most industries that operate in the Arctic, such as oil and gas or commercial fishing, require daily to three-day forecasts on where the sea ice edge is—the boundary between ice and open water. Tourism operators, on the other hand, might want seasonal information years ahead so they can plan when and where their cruise ships will go. Inaccurate or insufficient sea ice information can create situations where, for example, passenger ships or commercial vessels are entombed in ice and ultimately damaged or forced to abort their journey.
And while sea ice forecasts have traditionally provided information on the extent and movement of the ice, communities and industry also want to know about the concentration of the ice—is it thick, multiyear ice? Or slushy new ice that's easy to break through?
In the 1990s, Elizabeth Hunke, a developer at the Department of Energy's Los Alamos National Laboratory in New Mexico, created the model we use today to predict sea ice patterns in the Far North. Scientists input information on wind direction, ocean currents, air temperature, solar radiation, humidity, and sea surface temperature, and then see what the model churns out. "Typically, we run it alongside an atmospheric model or with an ocean model," Hunke said. Primarily, the model predicts the melting and growing of the sea ice, and the motion of the sea ice—how wind and ocean currents are pushing the ice around. Depending on what information is used, Hunke's model can provide information for different time scales—a week, a month, a season, or a millennium.
Over the past 20 years, refinements have been made to the model, but there has never been one big overhaul. "It's used by a lot of groups for very long-range climate situations—thousands of years—but these are 'projections,' not specific predictions of what's going to happen on January 1st, 2100," she said. Shorter-term predictions require in-depth knowledge of what the atmosphere is doing.
It's these shorter-term predictions, on what will happen weeks or months from now, that sea ice forecasters want to improve.
New data will help make such improvement goals a reality. NASA's long-planned IceSat-2 satellite is expected to launch later this year to gather three-dimensional information on the thickness of sea ice—something that has long evaded forecasters. The new polar-orbiting satellite NOAA-20, which launched in November of 2017, is also gathering critical sea ice information, providing observations down to less than a quarter-mile resolution. It can use moonlight to observe what the sea ice is doing at night.
Ultimately, the National Oceanic and Atmospheric Administration intends to add sea ice prediction to the overhaul of the U.S.'s current worldwide weather forecasting model, which makes predictions up to 16 days into the future. By including sea ice, which impacts global weather patterns, the nation is highlighting the importance of understanding how and where ice moves.
While sea ice forecasting has seen and will continue to see considerable advances, not all people are even able to use existing forecasts. The Sea Ice Prediction Network was created in 2013 and has been facilitating discussions and workshops between forecasters and users around the world over the past four years to determine how science can better serve the public.
In Tromso, forecasters learned that different industries used information differently. Fisheries, for example, might need their data in a different format from those working in oil and gas. Sea ice charts need to be available online to be downloaded to ships at sea or provided in high-resolution radar image maps that can aid in real-time navigation.
As an example of making sea ice predictions useful, Wiggins points to a novel project for northern communities—the Sea Ice for Walrus Outlook. This project provides forecasts for ice and weather to help subsistence hunters in Alaska predict where and when to hunt walrus. In turn, hunters can also share photos and reports to help other communities know what's happening on the ground, and provide validation for how well government sea ice forecasts are performing. She hopes these kinds of data-sharing projects could help ease daily life for the people who are expected to experience among the most rapid and dramatic effects of climate change.
"It's becoming more and more important to be able to provide people who live and work in the Arctic and who deal with ice to be able to predict [patterns]—for cost, for planning, for safety," she said.