Periscian (adj.)

1590s, "of or pertaining to the Periscii," the inhabitants of the Polar circle in ancient Greek imagination, literally (those) "throwing a shadow all round," from peri "round about" (see peri-) + skia "shade, shadow" (see, and compare, Ascians). So called because their shadows would revolve around them during the course of a summer day, when the sun is always above the horizon there.