In which atmospheric layer do we find an increase in temperature with height?

The proper answer involves understanding the temperature trends in various layers of the Earth's atmosphere. The thermosphere is characterized by a significant increase in temperature with height. This layer is situated above the mesosphere and can reach temperatures exceeding 1,000 degrees Celsius due to the absorption of intense solar radiation by the sparse gas molecules present. The high energy from the sun causes these molecules to move more rapidly, resulting in higher temperatures.

In contrast, in the troposphere—the layer closest to Earth's surface—temperature generally decreases with altitude. The stratosphere, which lies above the troposphere, shows an increase in temperature due to the presence of the ozone layer that absorbs harmful ultraviolet radiation from the sun, but this increase is not as pronounced as in the thermosphere. The mesosphere is notable for its decrease in temperature with height, which is why, at high altitudes in this layer, temperatures can drop significantly.

Therefore, the thermosphere is unique in that it experiences a dramatic increase in temperature with height, making it the right choice for this question.