Task: Class Definition Understanding (ontology: Earth_Environment/SWEET)

Which of the following definitions best describes 'mixed layer capping inversion'?

A. A cloud system that occurs in connection with an ensemble of thunderstorms and produces a contiguous precipitation area on the order of 100 km or more in horizontal scale in at least one direction. An MCS exhibits deep, moist convective overturning contiguous with or embedded within a mesoscale vertical circulation that is at least partially driven by the convective overturning.
B. The temperature to which a given air parcel must be cooled at constant pressure and constant water vapor content in order for saturation to occur.
C. The statically stable layer of air at the top of the atmospheric boundary layer. Because the troposphere is statically stable on the average (i.e., potential temperature increases with height), and because turbulence in the boundary layer causes potential temperatures to become somewhat well mixed there, conservation of heat requires that there be a potential temperature increase (i.e., a temperature step or inversion) at the top of the boundary layer. It is this inversion that separates the boundary layer from the rest of the troposphere by limiting the domain of turbulence. It is also responsible for trapping pollutants near the ground during fair weather.
D. A fault whose two sides have approached each other substantially in the direction perpendicular to the fault.

Answer: The statically stable layer of air at the top of the atmospheric boundary layer. Because the troposphere is statically stable on the average (i.e., potential temperature increases with height), and because turbulence in the boundary layer causes potential temperatures to become somewhat well mixed there, conservation of heat requires that there be a potential temperature increase (i.e., a temperature step or inversion) at the top of the boundary layer. It is this inversion that separates the boundary layer from the rest of the troposphere by limiting the domain of turbulence. It is also responsible for trapping pollutants near the ground during fair weather.