Stratosphere

What Is the Stratosphere?

Most aircraft reach their cruising altitude in the layer of the earth’s atmosphere that is called the stratosphere. It’s technically part of the biosphere, or the part of earth where life can exist, because of bacteria that are able to survive at that altitude and some birds may be able to fly in the lower parts of the stratosphere. Because temperatures are lower in the stratosphere, aircraft are more fuel efficient and there tends to be less turbulence.