The Navajo are the second largest tribe in the U.S. and they have the largest reservation stretching across Colorado, Utah, New Mexico and Arizona with over 25,000 square miles. They were also among the largest group of Indians to migrate to Los Angeles in the 1950s and 60s.
The ionosphere is a shell of electrons and electrically charged atoms and molecules that surrounds the Earth, stretching from a height of about 50 km (31 mi) to more than 1,000 km (620 mi).
Answer is Ionosphere. The ionosphere is a layer of ionized air in the atmosphere extending from almost 80 km above the Earth's surface altitudes of 600 km and more. Technically, the ionosphere is not another atmospheric layer. [ It occupies the same region of the upper atmosphere as the thermosphere. In this region of the atmosphere the Sun's energy is so strong that it breaks apart molecules. and atoms of air, leaving ions (atoms with missing electrons) and free-floating electrons. The ionosphere is the region of the atmosphere where the aurorae occur.