Climate of the Arctic continuously, with 30 stations in the Arctic from 1950 to 1991. These stations collected data that are valuable to this day for understanding the climate of the Arctic Basin. shows the location of Arctic research facilities during the mid-1970s and the tracks of drifting stations between 1958 and 1975. Another benefit from the Cold War was the acquisition of observations from United States and Soviet naval voyages into the Arctic. In 1958 an American nuclear submarine, the "Nautilus" was the first ship to reach the North Pole. In the decades that followed submarines regularly roamed under the Arctic sea ice,
North Pole will be entirely free of ice in the summer. This may have significant commercial implications; see "Territorial Claims," below. The retreat of the Arctic sea ice will accelerate global warming, as less ice cover reflects less solar radiation, and may have serious climate implications by contributing to Arctic cyclone generation. Polar bears are believed to travel rarely beyond about 82° North owing to the scarcity of food, though tracks have been seen in the vicinity of the North Pole, and a 2006 expedition reported sighting a polar bear just from the Pole. The ringed seal has also been seen at