Question

The stratosphere and mesosphere together are sometimes referred to as ______________.
A. Inner atmosphere
B. Middle atmosphere
C. Outer atmosphere
D. None of these

Answer 1

Hint: The stratosphere is bordered by the stratopause above, where the atmosphere becomes isothermal again. The mesosphere, reaching around 130 degrees below freezing, is the third and coldest layer of the Earth's atmosphere. The mesosphere is very important for the defense of the earth. Many meteors and asteroids are incinerated by the mesosphere before they can hit the earth's surface.

Complete answer:
The atmosphere of the earth has a series of layers, each with its own unique characteristics. These layers are called the troposphere, stratosphere, mesosphere, thermosphere, and exosphere, rising upward from ground level. Gradually, the exosphere fades away into the world of interplanetary space.
Stratosphere
A. The second layer is called the stratosphere, from the earth.
B. The stratosphere rises to about 50 km (31 miles) above ground from the tip of the troposphere.
C. Inside the stratosphere, the notorious ozone layer is located. In this layer, ozone molecules absorb ultraviolet ( UV) high-energy light from the Sun, turning the UV energy into heat.
D. In the lower stratosphere, commercial passenger jets travel, partially because this less-turbulent layer offers a smoother flight. The jet stream flows between the troposphere and the stratosphere, close to the boundary.
Mesosphere
A. The mesosphere is situated above the stratosphere.
B. It extends up to around 85 km (53 miles) above our planet in height. In the mesosphere, the bulk of meteors burn up.
C. Unlike the stratosphere, as you climb up into the mesosphere, temperatures once again get colder.
D. The air in the mesosphere is much too thin for breathing; the air pressure at the bottom of the layer at sea level is well below 1% of the pressure and begins to fall as you go higher.
E. The middle atmosphere is often referred to as the stratosphere and mesosphere. Gases consisting of various forms of atoms and molecules are extensively mixed together at the mesopause (top of the mesosphere) and below by atmospheric turbulence. Gas particles collide so rarely above the mesosphere, in the thermosphere, and beyond, that the gases become somewhat isolated based on the types of chemical elements they contain.

Hence, Option B, Middle atmosphere is the correct answer.

Note: The "ignorosphere" has been named the mesosphere because compared to the stratosphere (which can be reached with high-altitude balloons) and the thermosphere (in which satellites can orbit), it is poorly studied.