Surface-based temperature inversions are typically observed during what conditions?

Surface-based temperature inversions are most commonly observed during cloud-free nights in winter when the ground is dry due to the processes related to radiation cooling. During the night, the earth's surface loses heat through radiation, cooling down significantly. When the ground is dry, this cooling is more pronounced as there is less moisture available to retain heat.

In cloud-free conditions, there is no cloud cover to trap heat radiating from the Earth's surface, allowing temperatures to drop even further. As the surface cools, the air directly above it also cools, often resulting in temperature that is higher aloft compared to the cooler surface air, defining a temperature inversion.

This phenomenon can lead to stable atmospheric conditions, where the cooler, denser air remains trapped near the ground. Such inversions can also impact air quality by trapping pollutants close to the surface and can lead to fog formation.

In contrast, other conditions such as cloudy nights or summer days do not favor the development of strong inversions due to the insulating effect of clouds or heat from the sun, which keeps the surface air warmer.