Air molecules closer to the ground get their heat primarily through conduction and radiation from the ground itself. Here's how it works:

* Conduction: The ground absorbs solar radiation during the day, becoming warmer. This heat energy is then transferred to the air molecules directly in contact with the ground through conduction. The warmer molecules bump into cooler ones, transferring energy and warming them up.

* Radiation: The ground also emits infrared radiation, a form of heat energy. This radiation is absorbed by air molecules near the ground, raising their temperature.

Other factors contributing to air temperature near the ground:

* Solar Radiation: The sun is the primary source of heat for the Earth. While some of the sun's energy is absorbed directly by the air, a significant portion is absorbed by the ground and then transferred to the air through the mechanisms described above.

* Evaporation and Condensation: Water evaporating from the ground or bodies of water takes heat with it, cooling the air. Conversely, when water vapor condenses, it releases heat, warming the surrounding air.

* Air Movement: Wind can transport heat from warmer areas to cooler areas, influencing the temperature of air near the ground.

Overall, the process of heating the air near the ground is a complex interplay of these factors, but conduction and radiation from the ground are the most significant contributors.