How do scientists separate the layers of the atmosphere

Well, there are five layers in the Earth's Atmosphere:

(In order from the inside out)

1) Troposphere
- This is where weather occurs.

2) Stratosphere
- This is the layer where jets fly, this is where jet-streams are found

3) Mesosphere
- Meso ("Middle") named because it is in the middle. This is where meteros burn up in the atmosphere.

4) Thermosphere
- Thermo ("Heat") Names because it is the hottest layer in the atmosphere. This is where the aurora borealis, or northern lights occur.

5) Exosphere
- Exo ("Outer") This is the outmost layer and it is where the atmosphere merges with outer space.