Barents was of the opinion that twenty-four hours of continual daylight in the extreme north should make summer temperatures too warm for permanent ice, even at the North Pole. Further reducing the presence of ice, he surmised, was the saltiness of the sea, which chemically lowers the temperature at which ice forms. Together, these ideas led to the influential theory that an entire ocean extended, uninterrupted, from Alaska to Greenland and Siberia. This dream of an ice-free pole, known as the Open Polar Sea,
William Barents, born in 1550, was a Dutch navigator and cartographer. . .
