In the troposphere, the lowest level of the earth' s atmosphere, the temperature decreases as one progresses straight upward  At the top, the air temperature ranges from -50 degrees Celsius over the poles to -85 degrees Celsius over the equator  At that point the stratosphere begins, and the temperature stops decreasing and instead increases as one progresses straight upward through the stratosphere  The stratosphere is warmed by ozone
When an ozone particle absorbs a dose of ultraviolet sunlight, heat is generated
It is warmer at the top of the stratosphere over the poles than it is at the top of the stratosphere over the equator.