The development of thermals primarily depends on which factor?

The development of thermals primarily depends on solar heating. Thermals are upward currents of warm air that rise when the ground is heated by the sun. As the sun warms the surface of the earth, different materials (e.g., soil, vegetation, water) absorb and re-radiate heat at different rates, causing localized areas of warm air. This warm air becomes less dense than the surrounding cooler air and begins to rise, creating the thermal.

Solar heating is crucial because it initiates the process that leads to the formation of thermals. When the temperature difference between the ground and the surrounding air increases, thermals become stronger and more pronounced, providing lift for gliders and other aircraft. Understanding this relationship between solar heating and thermal development is essential for pilots, especially when planning for soaring flights or managing lift during ascent.

While wind patterns, humidity levels, and ground elevation can influence thermal behavior and intensity, they do not directly initiate their development as solar heating does. For instance, wind can cause thermals to be displaced horizontally or may cause them to weaken, but it doesn't create them. Humidity can impact the lift capabilities of a thermal by affecting air density, but is not a primary factor in their formation. Similarly, ground elevation can influence