conduction

One of the ways heat is transmitted in nature. It occurs through direct contact between two bodies or areas of the same material that are at different temperatures. That transfer of thermal energy takes place thanks to molecular agitation. Since air has low thermal conductivity, the Earth's surface only manages to heat a minuscule layer of atmosphere by conduction - barely 5 centimeters thick - resting on it. This heating of the air right at ground level promotes its ascent (as a consequence of the decrease in its density), with heat being transmitted from the bottom upward by convection.