Temperature gradient

The temperature gradient is a directed physical quantity that describes in terms of a mathematical gradient how much the temperature depends on the location and the direction in which she gets the strongest. His internationally used unit ( SI unit ) is Kelvin per meter (S / m). The temperature gradient drives the heat conduction and can cause currents (see Bénard experiment, Küppers - Lortz instability ). He plays in the thermophoresis and thermal osmosis an important role and is one of the causes of the weathering.

Is a temperature where the field without jumps in temperature, the temperature gradient is defined by the mathematical this temperature gradient field. The temperature gradient is thus a vector that follows the direction of the greatest local change in temperature and which is oriented in the direction of higher temperatures. If the temperature changes only in one spatial direction, the temperature gradient results in just as derivative of the temperature according to the spatial coordinate. At interfaces of materials of different temperature, the temperature gradient is mathematically undefined, neglecting the thermal boundary layer; clearly he goes there to infinity.

In meteorology, geology, and is mainly the vertical component of the temperature of interest, ie the change in temperature with distance from the surface. The vertical component of the temperature gradient in the atmosphere is called atmospheric temperature gradient and in the earth's geothermal depth level.

• Statistical Physics
• Thermodynamics
• Physical size