What is a downburst?

A downburst is characterized as a rapidly descending column of air that can produce intense straight-line winds at the surface. This phenomenon occurs when a pocket of cool air within a thunderstorm descends quickly due to its greater density compared to the surrounding air. When this descending air reaches the ground, it spreads out in all directions, creating powerful winds that can cause significant damage, similar to that of a tornado, but without the rotation.

The other options describe different meteorological phenomena. A thermal column of rising air refers to an updraft related to heating at the earth's surface, while a rotating column of air is more aligned with tornadoes, and a weak sea breeze typically involves gentle winds caused by temperature differences between land and water. These distinctions help clarify why the correct identification of a downburst relates specifically to its rapidly descending nature and the resultant straight-line winds.