A year-round Arctic expedition braving freezing temperatures and long periods of dark at the northern end of the Earth concludes on Monday, with German research vessel Polarstern's arrival home in Bremerhaven.
The ship was home to the Multidisciplinary drifting Observatory for the Study of Arctic Climate, or MOSAiC, which was trapped in Arctic ice all year round in what has been hailed as the first mission of its kind.
The Polarstern icebreaker left the ice floe on Sunday, according to a spokeswoman for Germany's Alfred Wegener Institute, which led the international study.
The vessel set off on September 20, 2019, from Norway's Arctic Circle city of Tromso.
Over the course of the expedition, hundreds of scientists collected data in the ocean, ice and atmosphere of one of the world's most hostile regions.
Experts hope the research will shine a light on climate change.
Over 70 research institutes from almost 20 different countries took part.
Time taken to prepare: a decade
Duration: 389 days
Budget: 140 million euros ($A228 million)
Participants: Around 100 scientists and crew for each leg, with five stages in all.
Nationalities: Over 70 research institutes from 20 different countries, led by Germany's Alfred Wegener Institute.
Size of the ice: When the vessel began drifting, the floe was around 2.5 km by 3.5 km. In places, it was just 30 centimetres thick, compared to several metres at its centre. After 300 days, the floe shrank during the Arctic summer to around 1 sq km and broke with a mighty crack.
Distance: The Polarstern drifted 3400 km.
Speed: Up to 25 km on a day with high winds, to less than 1 km on slower days.
Polar bears: Over 60 spotted on the Arctic ice.
New record: In February, the Polarstern drifted to a position of 88deg36' North, just 156 km from the North Pole. No other vessel has been further north in winter.
Coldest temperature: On March 10, the real temperature dropped to minus 42 degrees.
Polar night: The sun didn't show above the horizon for around 150 days.
Australian Associated Press