area of seasonal sea ice 2019-02-27T20:17:41Z An environmental zone which overlaps that part of an ocean or sea within which 1) sea ice is present only part of the year, 2) extends from the permanent ice zone to the boundary where winter sea ice extent is at a maximum, and 3) primarily overlaps first-year ice when seasonal ice is present. As this part of the environment is defined by a seasonal process, some of its differentia aren't physically there at all times of its existence.Thus, all boundaries of this entity are fiat. fiat part of an astronomical object