Yevgeny Korotkevich Yevgeny Korotkevich Yevgeny Sergeyevich Korotkevich () (1918 – 1 February 1994) was a Soviet scientist and polar explorer, Hero of Socialist Labor, and Doctor of Geographical Sciences. He was one of the leading scientists of the Arctic and Antarctic Research Institute (AARI) in the field of glaciology and geography of polar countries. Yevgeny Korotkevich participated in and headed many Arctic expeditions. In 1947-1955, he was engaged in scientific research on New Siberian Islands, Franz Josef Land, Novaya Zemlya, Severnaya Zemlya, Spitzbergen, Kara Sea islands, Taymyr Peninsula. Since 1955, Korotkevich's scientific and organizational activity was closely associated with the studies of
Novaya Zemlya effect gradient. The sunlight must bend to the Earth's curvature at least 400 km to allow an elevation rise of 5° for sight of the solar disk. The first person to record the phenomenon was Gerrit de Veer, a member of Willem Barentsz's ill-fated third expedition into the north polar region in 1596–1597. Trapped by the ice, the party was forced to stay for the winter in a makeshift lodge on the archipelago of Novaya Zemlya and endure the polar night. On January 24, 1597, De Veer and another crew member claimed to have seen the Sun appear above the horizon,