Rainfall associated with the Intertropical Convergence Zone (ITCZ), the belt of converging trade winds and rising air that encircles the Earth near the Equator, affects the food and water security of approximately 1 billion people worldwide. They include about 11% of the Brazilian population, concentrated in four states of the Northeast region—Rio Grande do Norte, Ceará, Piauí, and Maranhão. Large swaths of these states have a semi-arid climate, and about half of all their annual rainfall occurs in only two months (March and April), when the tropical rain belt reaches its southernmost position, over the north of the Northeast region. During the rest of the year, the tropical rain belt shifts further north. For example, it is responsible for peak rainfall in the coastal region of Venezuela in July and August.
Click here for original story, Marine sediments explain how part of Brazil’s Northeast region became semi-arid
Source: Phys.org