how does seasonal variations in SH in the tropics affect HC

• • ITCZ migrates seasonally north and south of the equator due to changes in solar energy received during the year 
  • This is due to the earth being tilted at about 23.5 on its own axis as it revolves around the sun. 
  • The tilt of the earth means that the overhead sun migrates between the Tropic of Cancer (in June) and the Tropic of Capricorn (in December) during the year.
• • When the sun is overhead the Tropic of Cancer, the northern hemisphere receives more insolation, causing the ITCZ to shift to the northern hemisphere. In December, when the sun is overhead at the Tropic of Capricorn, the ITCZ will have moved from the northern to southern hemisphere in the intervening time 
  • The ITCZ shifts seasonally, as the distribution of heat between the hemispheres changes with the migration of the overhead sun
  • As the ITCZ shifts, so do the Hadley cells