ATPL Meteorology Practice Test

The temperature range in the mesosphere is characterized by decreasing temperatures with altitude. In this atmospheric layer, which extends from about 50 km to 85 km above the Earth's surface, temperatures can indeed drop significantly, reaching lows around -90°C or lower, particularly near the stratopause at the upper boundary of this layer. As one ascends through the mesosphere, the air pressure and temperature continue to decrease, leading to extremely cold conditions.

This understanding aligns with the characteristics of the mesosphere, where the low temperatures result from the thinning atmosphere and the radiative cooling that occurs at high altitudes. Therefore, the choice that states a range of 0°C to -90°C accurately reflects the typical conditions observed in the mesosphere, even though the specific range might vary slightly depending on various factors such as solar activity and seasonal variations.

Overall, this makes the stated range of 0°C to -90°C the correct answer, as it encompasses the temperatures commonly expected in the mesosphere.