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Studying Arctic ice from cradle to grave

Researchers drill into the ice near RV Lance during the N-ICE test cruise in February 2014.
Researchers collect an ice core to measure its temperature and salinity near "RV Lance" during the N-ICE test cruise in February 2014.

When spring 2015 approaches, sun spilling the landscape will find a group of scientists adrift at sea on “RV Lance” – once a top-of-the-line seal hunting boat, now turned research vessel.

Location

On board the ship, an international collection of researchers will watch up-close as the arctic wakes, with instruments tuned not only to wildlife but to the most important creature of them all – the sea ice. 

“The ice itself has changed. It’s a new system, a different system of ice,” says Harald Steen of the Norwegian Polar Institute to BarentsObserver. “Through the winter we’ll study the ice, and when the sun returns we’ll be there to study the awakening of the Arctic ecosystem.” 

Steen is the project leader for the Norwegian Young Sea Ice Cruise (N-ICE2015). Scientists from the Norwegian Polar Institute, University of Bergen, Norwegian Meteorological Institute, Colorado State University and a dozen other research organizations will be on board “RV Lance” studying Arctic ice dynamics. The research vessel will go to sea late December 2014 and will freeze into the ice north of Nordaustlandet, Svalbard and passively drift with the ice through the winter. The “RV Lance” was chosen for its ability to withstand the crushing power of the winter ice. 

Dr. Harald Steen
Dr. Harald Steen, leader of the N-ICE2015 project and the Norwegian Polar Institute’s Centre for Ice, Climate and Environment (ICE).

The scientists are working to create a more accurate model of sea ice that is based on the first-year ice prevalent today, while the presence of multi-year ice diminishes. Multi-year ice is ice that survives the summer, builds up and becomes thicker over time. The first-year ice is saltier, melts faster and is flatter on the top and the bottom.

Steen’s report notes that September 2012 saw the smallest sea ice extent on record in the Arctic, and the rapid diminishing of the sea ice cover is noted by research organizations around the globe. In order to understand what the implications of decreasing Arctic ice are for the future, the world’s climate and ecosystems, scientists must first understand the current state of the ice. 

“Central to almost all aspects of Arctic system science is the problem of projecting the variations of Arctic climate during the next 100 years and beyond,” American researcher Donald Perovich wrote in an article about his 1997 SHEBA cruise. Similar to N-ICE2015, the SHEBA sea ice study performed off the Canadian coast focused on characterizing sea ice and its role in climate and the environment.   

But studies based on multi-year ice are must be paired with new research, Steen says, because multi-year ice is vanishing. Today, Arctic ice is a seasonal, “first-year” system that re-forms each year and melts 13cm more per month than multi-year ice. New models are needed in order to get an accurate picture. 

“Our climate models are based on multi-year ice,” Steen says to BarentsObserver. “We need to parameterize the energetics of the new first-year ice regime.” 

Sea ice reflects the sun’s energy, but first-year ice reflects 10% less energy back to the sky. Half of that energy is absorbed by the ice and the other half is transmitted into the water below. Increased absorption means larger melt ponds form on top of the ice which act like windows that allow the sun’s energy to penetrate the ice below. 

The flatness on the bottom of the ice means there are fewer habitats for crustacea, polar cod and other organisms that previously used the bottom of the ice for feeding and hiding from predators. The cruise will also assess changes in the Arctic algae bloom under the ice. Increased temperatures, for example, could give the algae different cues about when to bloom and change its natural cycle.

In addition to ocean-dwellers, animals like seagulls, seals and polar bears are affected by the shrinking ice. Gulls have to travel further to find food and after a certain distance the energy exchange for traveling for food does not match the amount of energy gained from the food they find, so the birds will have to move. When ice arrives later in the fall and ice cover is further away, polar bears can run out of country, Steen says. 

Turbulent Ocean

The drift trajectory of “Fram” in yellow and the projected drift trajectory of “RV Lance” in red starting north of Svalbard.

The N-ICE cruise will assess not only the ice and impacts on animal life, but the energy leakage from ocean to atmosphere and the turbulent mixing of water in the ocean. Fridtjof Nansen was a scientist who allowed his vessel to freeze into the ice north of Svalbard over a century ago. His ship, the legendary “Fram” (after which the Fram Centre in Tromsø was named) obtained information about underwater currents in the Arctic basin. Steen and N-ICE researchers will study the energy flux from the warm Atlantic water entering the Arctic ocean in the same area. 

“When Artic water mixes with salty, heavy Atlantic water, it causes turbulence that brings hot water to the surface. This combines with turbulence in the top layer of the ocean caused by drifting sea ice. These forces can bring the warm Atlantic water from a depth of 200m to the surface,” Steen says.

Paul Dodd is a physical oceanographer at the Polar Institute’s Centre for Ice, Climate and Ecosystems who will join the N-ICE cruise to study the temperature, salinity and pressure of the water beneath the ice, as well as obtain samples for chemical analysis to trace where the water came from. 

“I’m trying to find out how much freshwater there is in the Arctic Ocean and how much of it comes from different sources such as Siberian rivers, American rivers, precipitation, melting snow, the bearing straight inflow and of course melting sea ice,” Dodd said to BarentsObserver in an e-mail. “It’s quite likely that different amounts of freshwater come from different places at different times, depending on the atmospheric and oceanic circulation in the Arctic.” 

While smaller campaigns have studied first-year ice, N-ICE2015 will be the most comprehensive campaign to study first-year ice to date, Steen says. The six-month cruise will continuously record oceanographic, atmospheric and sea ice observations from the time young ice develops in winter and continue until the peak melting season in July. 

“Some of the work will be done using advanced remotely operated underwater vehicles and autonomous unmanned aerial vehicles (UAV). While “RV Lance” is in the ice, the area around her will also serve as a ground-truthed reference point for scientists working with remote sensing from satellite images or airplanes,” the work program states. The project, it says, is “a golden opportunity to do science in an area, and at a time of year, that has seldom been studied before.” 

The data on the behavior of the new first-year ice regime and the ecosystem that depends on sea ice, some of which will be available in real-time, will provide a needed set of longitudinal information over a six-month period. 

“The N-ICE cruise will look at the energetics of ice from formation mid-winter to melting next summer: from cradle to grave,” Steen says. “How the ice moves and behaves is important information both for ship traffic and for creating ice drift models that give clues about the future state of the Arctic.”