The Zhubov scale is a way of reporting

polar Polar may refer to: Geography * Geographical pole, either of the two points on Earth where its axis of rotation intersects its surface ** Polar climate, the climate common in polar regions ** Polar regions of Earth, locations within the polar circ ...

sea ice coverage. It was developed in the former

USSR The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

by Russian naval officer N. N. Zhubov (1895–1960) as a way for Soviet officers to describe ice coverage. The Zhubov scale is measured by using the unit ball, one ball equals 10% coverage, five balls 50% coverage and so on, with a total of ten unit balls being possible.

References

{{cartography-stub Sea ice