What characteristic do heat waves display?

Heat waves are typically characterized by the way they propagate through the atmosphere. The correct characteristic highlights that heat waves travel in a straight line. This is because heat energy moves from areas of higher temperature to areas of lower temperature, primarily in the form of infrared radiation. In a heat wave situation, the intense, hot air tends to create a stable layer of heat that does not mix with cooler air below, leading to a straight-line movement of heat radiation across a region.

Other characteristics related to heat waves, such as absorbing and reflecting heat, are influenced by the surface and atmospheric conditions but don't describe the primary behavior of heat waves effectively. Heat waves do not travel in circular patterns nor transfer heat through liquids as their main characteristic, as they are essentially a phenomenon of radiative heat transfer in the air. Understanding the linear propagation of heat waves helps contextualize their effects on weather and climate conditions, especially during extreme temperature events.