Intertropical Convergence Zone

Define the ITCZ.

The ITCZ is a belt of low pressure that circles the Earth near the equator.

What converges at the ITCZ?

Trade winds from the northern and southern hemisphere meet and converge in the ITCZ. As the trade winds converge, the air is forced to rise due to low pressure at the surface. This air cools and releases moisture through condensation.

What does the moist air result in?

High levels of atmospheric instability, leading to the development of thunderstorms and heavy rainfall.

What does the position of the ITCZ depend upon?

The position of the ITCZ varies seasonally depending on the tilt of the earth’s axis and its orbit around the sun. For example, in the Northern hemisphere summer, the North pole is tilted towards the sun, which causes the ITCZ to move northwards.

What makes the ITCZ path more wiggly?

 Land and ocean surfaces and mountain ranges can also influence the ITCZ.

How does the ITCZ impact temperature?

• Within the ITCZ temperatures are generally high and the region experiences a consistent and warm climate.

• The ITCZ is associated with intense vertical convection, which leads to air cooling adiabatically. This contributes to a decrease in temperatures with altitude. 

• The ITCZ brings warmer temperatures to the hemisphere experiencing summer.

• The ITCZ influences ocean currents, which can affect sea surface temperatures, thus impacting the climate of coastal regions.

How does the ITCZ impact precipitaion?

• Warm water near the ITCZ creates favourable conditions for the formation of tropical cyclones. This increases precipitation rates in affected areas.

• When the ITCZ is overhead regions may experience wet seasons, i.e frequent and intense rainfall.

• When the ITCZ moves away a dry season may begin.