GAC in Hadley Cells affect rainfall

• How does the atmospheric circulation in the Hadley cells affect rainfall in the tropics

  • The upward movement of air at the ITCZ (due to convergence and convection) favours the formation of heavy precipitation. As the air expands upwards at the ITCZ, it cools and condenses, forming clouds 
  • The ITCZ is thus the rainiest latitude zone in the world. This explains why the ITCZ observable on satellite images as a band of thick clouds and rain 
• • In contrast, at the subtropical highs, air warms as it descends, suppressing condensation and cloud formation. Thus, as the descending limb of the Hadley cell, dry conditions are common