What is the significance of an inversion layer regarding moisture?

The significance of an inversion layer regarding moisture lies in its ability to trap humidity and pollutants near the Earth's surface. An inversion layer occurs when a layer of warmer air sits above cooler air, effectively acting as a cap that prevents vertical mixing of the atmosphere. This stratification can lead to a concentration of moisture, as cool air, which is denser and can hold less moisture than warmer air, gets 'trapped' underneath. As a result, any humidity present in that cooler air can accumulate, and pollutants released at the surface also become confined within this layer.

Inversions are particularly common in urban areas, leading to issues such as smog, where both moisture and particulates can create poor air quality. This trapping mechanism is significant for understanding weather patterns, air quality issues, and how moisture interacts with local climates.

The other options do not accurately correspond to the effects of an inversion layer; they suggest conditions that are not typically associated with the characteristics and impacts of inversion layers on atmospheric moisture.