Energy balances
Urban heat islands

The climatic variations of a territory are controlled by the energy balance on its surface. This energy balance describes the net result of energy exchange (i.e. flux densities in W · m ^–2 ) by radiation, conduction and convection between a land surface and the atmosphere.

In the next two sections, the energy balances of a rural and an urban surface will be presented (figures 2 and 3 ). These energy balances are different, which is why the urban heat island phenomenon exists.