Thermospheres

Part of speech: noun

Definitions

1. A layer of Earth's atmosphere situated above the mesosphere, characterized by increasing temperatures with altitude
2. A region where solar radiation significantly affects temperature and the behavior of gases
3. The uppermost layer of the atmosphere, hosting ionized particles and playing a key role in atmospheric dynamics and space weather

Etymology: The thermosphere is a layer of the upper atmosphere, and its name is a modern construction built from two Greek words. "Thermos" is Ancient Greek for "hot," and "sphaira" means "sphere" or "ball," which reached English through Latin "sphaera" and Old French "sphere." The "-sphere" element was later used in English to name atmospheric layers, so the name literally describes a hot sphere of air rather than a place the Greeks ever imagined. The plural "thermospheres" is simply the regular plural of "thermosphere," used when more than one such layer is meant, such as the thermospheres of different planets. Because the term is a scientific coinage, the word reflects the Greek roots only in its parts, not in any ancient atmospheric theory.

Synonyms: atmospheric layers