State Fire Inspection Practice Exam

The phenomenon where a layer of air is warmer than the air below it is called temperature inversion. This occurs when the normal temperature gradient of the atmosphere, where temperature decreases with altitude, is reversed. In a temperature inversion, warmer air traps cooler air beneath it, which can lead to various atmospheric effects.

One significant consequence of temperature inversion is the potential for the buildup of pollutants near the ground because the stable warmer air inhibits vertical mixing, causing air quality to decline. This phenomenon is also critical in fire behavior, as inversions can affect fire spread and smoke movement by altering wind patterns and heat transfer mechanisms. Understanding temperature inversions is essential for fire inspectors and responders, as they must account for these conditions when assessing fire risks in an area.

The other choices do not directly relate to this specific atmospheric condition. Thermal expansion refers to the increase in volume or change in state of a substance when it is heated, atmospheric pressure is the weight of air in the atmosphere, and humidity increase pertains to the amount of moisture in the air. None of these accurately describe the situation of a warmer air layer above cooler air.