Thermal equator
Also called: Heat equator · Topic: Solar Radiation, Heat Balance and Temperature · NCERT: Class 11, Ch 8 "Solar Radiation, Heat Balance and Temperature"; Class 11, Ch 12 "Water (Oceans)"
Meaning
The thermal equator is the belt of highest temperature around the Earth. It does not lie on the geographical equator. On average it is about 5°N, because the Northern Hemisphere has more land, and land heats up more than the sea. It moves north and south during the year, following the overhead Sun. It moves much further over land than over the oceans. It roughly follows the ITCZ (Inter-Tropical Convergence Zone, the low-pressure belt where the trade winds from the two hemispheres meet).
Example
In July, the thermal equator moves far north over the land. It reaches South Asia, including north-west India and Pakistan, and the Sahel belt, which lies just south of the Sahara in Africa.
Don't confuse with
- Geographical equator: it is the fixed 0° line of latitude. The thermal equator is a belt of greatest heat that moves through the year.