noun
thermosphere
Scientific term for the atmospheric layer above the mesosphere, where temperature increases with altitude.
熱圏は中間圏の上に位置する大気の層です。
The thermosphere is the atmospheric layer located above the mesosphere.
オーロラは熱圏で発生します。
Auroras occur in the thermosphere.
Compound of 熱 (netsu, 'heat') and 圏 (ken, 'sphere, zone'), referring to the hot atmospheric layer.