Question

2. Why aeroplanes and jets fly in the stratosphere?
3. Why is the upper part of the thermosphere known as ionosphere
4. How is aurora formed?​

Answer 1

At heights of above 80 km (50 mi), in the thermosphere, the atmosphere is so thin that free electrons can exist for short periods of time before they are captured by a nearby positive ion. ... This portion of the atmosphere is partially ionized and contains a plasma which is referred to as the ionosphere

Answer 2

Answer:

Commercial jet aircraft fly in the lower stratosphere to avoid the turbulence which is common in the troposphere below. The stratosphere is very dry; air there contains little water vapor. Because of this, few clouds are found in this layer; almost all clouds occur in the lower, more humid troposphere.