释义 |
heterosphere [`hed·ǝ·rǝ´sfir] METEOROLOGY The upper portion of a two-part division of the atmosphere (the lower portion is the homosphere) according to the general homogeneity of atmospheric composition; characterized by variation in composition, and in mean molecular weight of constituent gases; starts at 50-62 miles (80-100 kilometers) above the earth and therefore closely coincides with the ionosphere and the thermosphere. |