The temperature gradient in a given direction from a given spatial starting point is the rate at which temperature changes relative to distance in that direction from that point.
The world temperature gradient is the rate at which temperature changes between the Earth's poles and the equator. In each hemisphere the temperature gradient from pole to equator is steeper in that hemisphere's winter than in its summer.
See also
Gradient
Sources
"The temperature gradient and pressure gradient." The Weather Prediction.com. Accessed on January 30, 2005.
"Temperature gradient." Hyperdictionary.com. Accessed on January 30, 2005.
"Temperature gradient." The American HeritageŽ Dictionary of the English Language, Fourth Edition. Accessed on January 30, 2005.