Soil Temperature Profiles
The heat is continuously moving in to or out of the soil and thermal energy is being continuously redistributed in the soil. Heat will not flow under isothermal condition.
The pattern of soil temperature profiles changes rapidly during & normal day. The soil surface is the coldest level in the early morning and the warmest in the early afternoon.
At midday heat is directed downward through the upper one metro soil. The profiles show that the heat exists from middle of the layer after sunset but some heat flow continuously downward throughout the night. During most of the day temperature profile indicate downward heat flux. This is summer there is a net daily gain or storage of heat in the soil.