The stratosphere is above the mesosphere.
Mesosphere . The stratosphere , mesosphere and lowest part of the thermosphere are collectively referred to as the `` middle atmosphere '' , which spans heights from approximately 10 km to 100 km . The stratosphere ( [ ˈstrætəˌsfɪər , _ - toʊ - ] ) is the second major layer of Earth 's atmosphere , just above the troposphere , and below the mesosphere .