Figure 3 – (a) processes of heating and cooling of atmosphere and (b) per cent share of processes in heating up of atmosphere

4. Advection: The transfer of heat through horizontal movement of air is called advection. These winds take the characteristics of their source of origin with them. The temperature of a place will rise if it lies on the path of winds coming from warmer regions. The temperature will fall if the place lies on the path of the winds blowing from cold regions. Horizontal movement of the air is relatively more important than the vertical movement. In summer seasons, ‘Loo’ of north India is a hot wind and ‘Sirocco’ is also a hot wind carries heat of Sahara desert to Mediterranean regions. In middle latitudes, most of diurnal (day and night) variation in daily weather is caused by advection alone.