Geir Jenssen (born 30 May 1962) is a Norwegian electronic musician who records as Biosphere.
A resident of Tromsø within the Arctic Circle, Jenssen is well known for ambient and ambient house pieces, often inspired by Arctic or mountain settings, and his use of loops and peculiar samples from science fiction and natural sources.
His 1997 album Substrata was voted by the users of the Hyperreal website in 2001 as the best all-time classic ambient album.