What is necessary for understanding the behavior of passive plumes in the atmosphere?

Understanding the behavior of passive plumes in the atmosphere requires knowledge of wind speed uniformity because passive plumes, which are typically released from a source due to buoyancy or momentum, will disperse primarily due to the wind conditions in the atmosphere. When wind speed is uniform, it simplifies the prediction of plume trajectory and dispersion patterns, as the plume will be carried consistently in the direction of the wind without significant variation in speed or direction.

Wind speed variations can lead to complex behaviors, such as turbulence or meandering of the plume, making it challenging to model or predict its spread accurately. Hence, uniform wind conditions help in creating more straightforward models for dispersion, allowing for easier planning and assessment of potential impacts from the plume.

High humidity, low temperature, and geographical complexity can influence plume behavior to some extent but are not foundational in the way that wind conditions are. High humidity may affect the plume's density and buoyancy, low temperatures could impact atmospheric stability, and geographical complexity could create localized effects, but without uniform wind speed, these factors can be significantly less predictable.