Is the aurora borealis found in the thermosphere or the mesosphere?

The aurora borealis, or northern lights, occurs in the thermosphere, which is located above the mesosphere. This phenomenon is caused by charged particles from the sun interacting with the Earth's magnetic field and atmosphere at high altitudes, typically between 80 to 300 kilometers (50 to 200 miles) above the Earth’s surface. The energy from these interactions produces the beautiful light displays characteristic of auroras.