What does the term "temperature inversion" refer to in meteorology?

The term "temperature inversion" in meteorology specifically refers to a phenomenon where a layer of warmer air is situated above cooler air. This occurs when the normal temperature gradient in the atmosphere is inverted, meaning that instead of the temperature decreasing with altitude, it increases. This situation can lead to various weather phenomena, including the trapping of pollutants and fog formation, because the warmer air aloft acts as a lid, preventing the cooler air below from rising and dispersing.

In meteorological terms, an inversion can significantly impact local weather conditions and air quality. For instance, when a temperature inversion is present, it can lead to stagnant air conditions and reduced visibility. Understanding temperature inversions is crucial for pilots, as they can influence flight operations and turbulence levels.

The other options do not accurately represent the concept of a temperature inversion in meteorology. A sudden rise in atmospheric pressure does not describe any layering of air, while cool air settling in low areas is a consequence of density differences, not an inversion. Increased turbulence due to wind shear relates to wind differences at varying altitudes rather than the layering of temperatures that characterize an inversion.