Question

If the air all around the equator has low pressure and low density then what type of air is it? What does that type of air do in the atmosphere?

Answer 1

It is the same type or composition as the rest of the atmosphere, but because it gets heated it is less dense and it rises.

Explanation:

Rising air in the tropics is called the Intertropical convergence zone and is a region of rising hot air. As it rises, the moisture in the air eventually reaches its saturation point and the moisture falls out as rain. This is why the tropics are know for their very heavy rainfall periods

The ITCZ and other major atmospheric cells control the major biomes on the planet - see figure.