| Webster's Online Dictionary |
| Expressions | Domain | Definition | |
| Effective atmosphere | Aerospace | 1. That part of the atmosphere which effectively influences a particular process or motion, its outer limits varying according to the terms of the process or motion considered. For example, an earth satellite orbiting at 250 miles altitude remains within the ionosphere, but because the air particles are so sparse at this altitude as to cause no appreciable friction of deflection, the satellite may be considered to be outside the effective atmosphere. For movement of air vehicles the effective atmosphere ends at the aeropause (which see).2. = optically effective atmosphere. (references) | |
| Optically effective atmosphere | Aerospace | That portion of the atmosphere lying below the altitude from which scattered light at twilight still reaches the observer with sufficient intensity to be discerned. Also called effective atmosphere. The top of this region lies between 50 and 60 kilometers. (references) | |
Source: compiled by the editor from various references; see credits. | Top | ||
