Which factors affect the strength of mechanical turbulence?

The strength of mechanical turbulence is primarily influenced by the speed of wind, terrain roughness, and air stability.

Wind speed plays a crucial role because stronger winds tend to promote greater turbulence by generating more chaotic airflow as they interact with the surface of the Earth and obstacles like buildings or trees. Terrain roughness comes into play because areas with rough terrain create more friction against the wind, leading to increased turbulence as the airflow is disrupted. Furthermore, air stability is essential; stable air layers tend to suppress turbulence, while unstable conditions encourage vertical mixing and turbulence development.

Considering the other options, factors like altitude and pressure changes, humidity, and time of day, while relevant to meteorological phenomena, do not specifically address the mechanical aspects of turbulence. They may influence weather patterns or conditions but do not directly impact the mechanical turbulence generated by wind interacting with the Earth's surface. Therefore, the focus on wind speed, terrain roughness, and air stability in the correct answer provides a comprehensive understanding of the situation.