Heat Belts
Why in News?
- A new study recently reveals the emergence of an “extreme heat belt” in the United States, which is likely to spread to other regions of the world by
In Terms of Heat Belt:
- The Heat Belt is a belt of extreme heat where there is at least one day per year in which summer temperatures reach 125 Fahrenheit (52०C).
- The developing “Extreme Heat Belt” creates an area of vulnerability for most of the US states.
- It was projected that the extreme heat belt would increase from 50 counties in 2023 to more than 1,000 by 2053.
Calculation of Heat Index:
- Heat index is a parameter that considers both temperature and humidity to calculate the apparent temperature or “feels like” temperature to humans.
- It helps understand the effect of humidity at high temperatures and how it contributes to human discomfort during hot weather.
- Heat index launched by India Meteorological Department (IMD) on experimental basis.
- It is intended to provide general guidance for areas with high apparent temperatures that cause discomfort to people.
Classification of Temperature Belts of the World: 
- Sun is the main source of atmospheric temperature. In fact, the atmosphere receives very little heat energy from the Sun, as it receives most of its energy from long-wave terrestrial radiation.
- Temperate Zone: The temperate zone is located between 23.5 degrees and 66.5 degrees in the Northern and Southern Hemispheres. The northern temperate zone is located between the Arctic Circle and the Tropic of Cancer. The southern temperate zone is located between the Antarctic Circle and the Tropic of Capricorn.
- Tropical Zone: The tropical zone is the largest thermal zone and is located between the Tropic of Cancer and the Tropic of Capricorn. This is the hottest region of the Earth. The area from the Tropic of Cancer (23.5°N) to the Tropic of Capricorn (23.5°S) across the Equator (0°) is considered the tropical region. The sun rays fall directly at least once a year.
- Frigid Zone: This is the coldest region of the earth. This region is located north of the Arctic Circle (66.6°N) and south of the Antarctic Circle (66.5°S) and is permanently frozen. There is no sunlight in this area for most months of the year.
Importance of Thermal Zones:
- This division of the Earth into different heat zones helps in understanding the climate changes and to study weather conditions across the world.
Source – Indian Express
