FAA Ground School Practice Test

Low-level turbulence can occur and icing can become hazardous in which type of fog?

1. Advection fog

2. Steam fog

3. Radiation fog

4. Upslope fog

The correct answer is: Steam fog

Steam fog, also known as sea smoke, forms when cold air moves over warmer water, leading to the rapid evaporation of water and subsequent condensation of that moisture in the colder air above. This phenomenon can create dense fog, and conditions often associated with steam fog, such as low temperatures and high humidity, can contribute to low-level turbulence. Additionally, the presence of warmer water can lead to moisture in the air that may freeze upon contact with supercooled surfaces, resulting in icing conditions. This is particularly hazardous for aviation because both low-level turbulence and icing can significantly impair aircraft performance and safety. While advection, radiation, and upslope fogs have their own characteristics and risks, they do not generally lead to the same level of turbulence and icing hazards as steam fog does, thus making steam fog the most relevant choice concerning both low-level turbulence and potential icing.