Answer:
Imagine a natural phenomenon that is so powerful that it controls the lives of millions of people. A natural force so great it influences migration, wildlife, poverty, the shape of the land and controls the climate of whole parts of a continent.
This force of nature is not volcanoes, earthquakes or fiction….it is the ITCZ or the Inter-tropical convergence zone – the coming together of air masses.
So let’s explore this aspect of the atmosphere and its influence on the wet and dry seasons of West Africa.
This is thinkfour.
The ITCZ stands for the Inter-tropical convergence zone.
The words ‘inter-tropical’ means it sits between the tropics north and south of the Equator.
The word convergence refers to where the trade winds meet at the base of the Hadley Cells either side of the equator
Where the trade winds meet at the equator a zone of low pressure is created. Here, warm air rises through convection. As it does so it draws in air from 30 degrees north and south. As the warm air rises it chills and condenses to cause storm clouds and heavy rain.
This next part, is key.
The ITCZ moves north and south throughout the year following the Thermal Equator. This is the movement of the Sun in relation to the Earth’s surface. It alters where the most heat is received and where convection takes place.
The rainfall produced controls the wet and dry seasons in West Africa.
As the ITCZ follows the Thermal Equator it controls the movement of two key air masses which affect the climate.
The Trade Winds pull in the Tropical Maritime and Tropical Continental air masses and meet to form the ITCZ.
The Topical Maritime air mass originates mainly over the Atlantic and so carries a lot of moisture. It is unstable, warm and humid as is created near the tropics. It brings rain to West Africa.
The Tropical Continental air mass is the opposite. It is formed over the Sahara Desert. Consequently, it is dry, warm and stable with warm winds called Harmattan.
Explanation:
that is my answer ^^
