Intertropical convergence zone (ITCZ)

• Where tropical continental air mass and tropical maritime airmass meet it is called the ITCZ.
• Tropical continental air mass forms over the Sahara desert.
• Tropical continental brings warm, dry, stable air. Weather: low humidity, very warm, no rain/clouds, warm dry harmattan wind, weather is repetitive.
• Tropical maritime air mass forms over the Atlantic ocean.
• Tropical maritime brings warm, wet air. Weather: High humidity, unstable air which causes rain and thunderstorms, high temperatures, weather pattern varies.
• The ITCZ is positioned over the equator in March and September.
• The ITCZ changes position throughout the year in relation to the apparent movement of the sun because of the way the Earth sits on its axis.
• In July: The sun is directly overhead the Tropic of Cancer due to Earths tilt, the ITCZ migrates North from January to July and is positioned over the TO Cancer.
• In July: Africa dominated by mT air mass which is why July is Africas wet season.
• In January: The sun is directly overhead the Tropic of Capricorn due to Earths tilt, the ITCZ migrates South from July to January and is positioned over the TO Capricorn.
• In January: Most of Africa is influenced by cT air mass which is why most of Africas dry season is at this time of year.