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In meteorology, the upper of two portions of the atmosphere as distinguished by the general homogeneity of their composition (the other portion is the homosphere); it begins at 80 to 100 kilometers above the earth, closely coinciding with the ionosphere and the thermosphere, and is characterized by variation in composition and mean molecular weight of constituent gases.
This entry is located in the following units: heter-, hetero- (page 8) sphero-, spher-, -sphere- (page 8)
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The upper portion of the atmosphere approximating the region of the thermosphere and the ionosphere.

The heterosphere includes the layers of the thermospere and the exosphere.

This entry is located in the following unit: Meteorology or Weather Terms + (page 4)