Melting sea ice and polar bears: A Wellington physicist's Arctic expedition

Polar bears liked to come and check out the equipment. Photo / Supplied

A Wellington scientist returning from brushes with polar bears the North Pole has urged New Zealand to invest in research into the climatic impacts on sea ice.

Victoria University Antarctic Research Centre research fellow Dr Ruzica Dadic has just returned from the international MOSAiC expedition to the Arctic, the largest polar operation of its kind in history.

The expedition used state-of-the-art instruments to study sea ice physics and surface processes, but this often attracted unexpected visitors.

"Polar bears would come to check out the equipment – they're playful, enquiring creatures," Dadic said.

"We avoided them so as not to harm them. Whenever we saw a polar bear, we went back to the ship.

"You just had to abandon all your stuff, unplug all the power in case they nibbled on the cords and the polar bear would come and sniff it, while you worried about your expensive equipment."

The Arctic is regarded as "ground zero for global warming" and Dadic said the sea ice was disappearing fast.

"There's the potential for big changes that we don't properly understand," she said.

Melting ice also had a direct impact on the expedition, with the icebreaker ship Polarstern frozen into the ice to act as a research base.

"The idea was to stay in the same spot, but the ship melted out in July so they had to find a new sea ice flow and re-freeze it in," Dadic said.

As a snow and ice physicist, Dadic studied the topmost layer of sea ice while on the expedition.

"Usually this is snow but once the snow went away it was mushy, melty sea ice," she said.

The melting of the snow would affect ocean temperatures, she said, something she hoped New Zealand would invest more research into.

"If the ice melts, the ocean will absorb 90 per cent more energy and heat up," she said.

"There's a feedback loop, so once this gets started, there's a runaway effect.

"For New Zealand, so close to Antarctica, it's important that we understand the climate impacts of sea ice, and snow on sea ice. None of this has been studied enough."