fluid. n. 1. (General Physics) a substance, such as a liquid or gas, that can flow, has no fixed shape, and offers little resistance to an external stress. adj. 2. (General Physics) capable of flowing and easily changing shape.
The thermosphere layer. The thermosphere layer is called the thermal layer as it is the hottest layer of the atmospheric envelope . It is the fourth layer of the atmospheric envelope, The temperature of the thermosphere layer increases with a high rate as we go up until it reaches 1200 degree Celsius
Within this layer, temperature increases as altitude increases (see temperature inversion) ; the top of the stratosphere has a temperature of about 270 K (â3 Â°C or 26.6 Â°F), just slightly below the freezing point of water.his is in contrast to the troposphere near the Earth's surface, which is cooler higher up and warmer farther down. The border of the troposphere and stratosphere, the tropopause, is marked by where this inversion begins, which in terms of atmospheric thermodynamics is the equilibrium level.