Final answer:
Within a thunderstorm cell, the temperature decreases with increasing altitude due to adiabatic expansion as the air rises to areas of lower pressure and cools by doing work on the surrounding air.
Step-by-step explanation:
Within a thunderstorm cell, the temperature decreases with increasing altitude primarily because of the expansion of rising air within the cloud.
The reason for the temperature decrease is due to the process of adiabatic expansion. As the air rises within the thunderstorm cell, it moves to areas of lower atmospheric pressure. With less pressure restricting the air, it expands. Since no heat is being added (the expansion is adiabatic), the expanding air does work on the surrounding air and cools as a result. This phenomenon is closely related to the principle that says, when a gas expands without receiving heat, its temperature drops. This is in line with the gas laws in thermodynamics which relate pressure, volume, and temperature.
Additionally, there are other factors that can influence temperature changes within a thunderstorm, such as the release of latent heat during condensation when water vapor turns into liquid. However, the primary cause for the temperature decrease with increasing altitude is the adiabatic expansion of the air.