The ionosphere is a layer of the atmosphere located inside the blank?

The ionosphere is a layer of the atmosphere located inside the thermosphere, which is situated above the mesosphere and below the exosphere. It extends roughly from about 30 miles (48 kilometers) to 600 miles (965 kilometers) above the Earth's surface. This region is characterized by a high concentration of ions and free electrons, which can reflect and refract radio waves, affecting communication and navigation systems.