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The layer of the Earth's atmosphere directly above the mesosphere and directly below the exosphere.

Earth's night-side upper atmosphere appearing from the bottom as bands of afterglow illuminating the troposphere in orange with silhouettes of clouds, and the stratosphere in white and blue. Next the mesosphere (pink area) extends to the orange and faintly green line of the lowest airglow, at about one hundred kilometers at the edge of space and the lower edge of the thermosphere (invisible). Continuing with green and red bands of aurorae stretching over several hundred kilometers.

The layer of the Earth's atmosphere directly above the mesosphere and directly below the exosphere.

A diagram of the layers of Earth's atmosphere

The layer of the Earth's atmosphere directly above the mesosphere and directly below the exosphere.

Figure 1. Diagram shows: Electric Conductivity (lines on left, scale above), including DYNAMO REGION — Temperature (line in center, scale below), LOWER is Troposphere, MIDDLE is Stratosphere and Mesosphere, UPPER is Thermosphere and Exosphere — Electrons per m3 (line on right, scale above), the start of the inner Van Allen belt