Ice spies

The RV Polarstern will park itself in the Arctic Ocean for a year. Its data harvest should help counter climate change, says Prasun Chaudhuri

By Prasun Chaudhuri
  • Published 14.05.18
Polarstern on an earlier expedition to the  central Arctic.

In 1893, Norwegian explorer and zoologist Fridtjof Nansen set off on a mission to the North Pole in a wooden vessel named Fram. His plan was to steer the manoeuvrable ship, made of the toughest oak timbers, in such a way that it got engulfed by sea ice and then use the natural drift of polar ice to reach the North Pole. All this would, of course, happen during peak winter.

Many experienced polar explorers, such as Sir Allen Young and Sir Joseph Hooker, were dismissive of this audacious and "illogical scheme of self-destruction". Ultimately, neither Nansen nor Fram could hit the pole, but three years later the ship was back in Oslo. Nansen's account of the journey across the desolate wastes of ice turned out to be one of the most dramatic narratives in the annals of polar exploration. The Fram returned to port in triumph, bringing with her a wealth of valuable scientific material from regions of the earth never before visited by man. This included data on weather patterns of the remote ice world.

Now, 125 years after Nansen's Fram expedition, scientists are planning to retrace the voyage to gather new insights on the Arctic region where climate is changing fast. The Multidisciplinary drifting Observatory for the Study of Arctic Climate (or Mosaic) mission will leave Norway in the fall of 2019, cruising to a point north of the Siberian archipelago, across the Fram strait, and then steer to a point where the ship will stay stuck for a year, or so.

The ship is the German research vessel Polarstern. Commissioned in 1982, the icebreaker is mainly used for research in the Arctic and Antarctica by the Alfred Wegener Institute (AWI) for Polar and Marine Research in Bremerhaven in northern Germany. While most ships want to avoid getting caught in deep ice, the Polarstern will willingly get ice bound so that scientists onboard can study the Arctic system - its drifting ice, the ocean hidden underneath and the health of the living organisms in it.

Prof. Dr Karin Lochte, director of the Alfred Wegener Institute, told KnowHow, "The Arctic is a key area for global climate change. Yet understanding of key climate processes in the Arctic is limited by lack of observation." This is the reason many processes in the Arctic climate system is not well represented in global climate models - mathematical representations of the climate system run on powerful computers - which are the best tools for projecting future climate change.

Scientists believe the Arctic Ocean is a carbon sink which guzzles more greenhouse gases than it belches, courtesy a wide variety of phytoplankton that absorb carbon dioxide - it's a mystery how these tiny creatures survive in the cold through long periods of darkness. However, researchers do not have a clear understanding of how the weather system in the Arctic works and the role sea ice plays in the regulation of heat, humidity and salinity.

Sea ice isolates the warm sea surface from the cold polar atmosphere. "It also provides an important habitat to a number of organisms ranging from microalgae to polar bears," says Lochte.

The helipad on the ship

In recent times, the Arctic ice sheet has shrunk considerably with temperatures rising several degrees above the long-term average. Prof. Markus Rex, the leader of the Mosaic project, said at the annual meeting of American Association for the Advancement of Science (AAAS) in Boston last year, "The decline of Arctic sea ice is much faster than climate models can reproduce and we need better climate models to make better predictions for the future."

Scientists study the Arctic climate based largely on data collected from remote artificial satellites. But, there are many small-scale processes and forces that are not well understood, because carrying out ground-based studies in the region is difficult.

The backbone of Mosaic will be the year-round operation of RV Polarstern, drifting with the sea ice across central Arctic from 2019 to 2020. "The ship's crew will fix multiple sensors across all levels of the environment, stuck amidst the ice," said Dr Rainer Knust, AWI's scientific co-ordinator for RV Polarstern, a research ship which has touched the North Pole several times. Weather balloons will monitor the air and research aircraft, carrying electromagnetic sensors, will measure the thickness of the ice. The researchers will leave behind some sensors, which can be remotely operated for future readings.

Helicoptors flying in via a fuel depot on Bolshevik Island in the Russian Arctic will ensure that the ship can be accessed all year round.

Prof. Rex, the German scientist affiliated to the AWI, said that the expedition will be nearly fully-funded [approximate cost is 63 million euros] with contributions from a consortium of international partners, including Germany, Russia, the US and China.

The Mosaic expedition is expected to transform our understanding of climate change in the Arctic, which is occurring faster than anywhere else on Earth. Warm spells in the Arctic have already been linked to an unusually low harvest in some areas of the Northern Hemisphere. The large-scale changes that occur in the Arctic climate system exert a strong influence throughout the globe; the Arctic plays an important role in balancing the world's climate.

Says Lochte, "The goal of the expedition is to improve the understanding of atmosphere-ice-ocean ecosystem processes in the central Arctic to support improved sea ice forecasting, regional weather forecasting and more accurate climate predictions."

The Fram expedition was groundbreaking. Mosaic is expected to carry its legacy forward.