As one moves from the equator towards the poles, steadily decreasing temperatures are observed. In the same way, there is a steady decrease of temperature with increasing elevation in the atmosphere. This decrease of temperature with increasing altitudes in the atmosphere is called the vertical temperature gradient.
Vertical temperature gradients are controlled partly by energy transfers and partly by vertical motion in the air. However, various factors affecting the vertical temperature gradient interact in a complex manner.
Energy transfers involve the latent heat of condensation, cooling of air by the process of radiation, and sensible heat transfer from the ground. Vertical motion is closely related to the pressure systems.
High pressure systems produce descending air currents which lead to warming of extensive layers of air. This results in the decrease of vertical temperature gradient. On the other hand, low-pressure systems give rise to ascending air currents which cool by expansion.
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This increases the vertical temperature gradient. Moisture is said to be an additional factor which creates a lot of complications in the vertical distribution of temperature.