The inside of a car parked in the sun heats up significantly due to the greenhouse effect. Sunlight enters the car through the glass, which is transparent to visible light and some infrared radiation. The car’s interior absorbs this solar radiation and heats up, including the car’s seats, dashboard, and other surfaces. These heated surfaces then emit infrared radiation, but the glass is opaque to this longer-wavelength infrared radiation, trapping the heat inside the car.
Here’s a more detailed explanation:
Sunlight’s Entry:
Short-wavelength radiation (visible light and some infrared) from the sun enters the car through the glass windows.
Absorption and Heating:
The car’s interior surfaces, like the seats and dashboard, absorb this sunlight and heat up.
Re-radiation:
The heated surfaces then emit infrared radiation, which has longer wavelengths than the sunlight.
Trapped Heat:
The glass windows, however, are opaque to the longer-wavelength infrared radiation emitted by the car’s interior. This means the heat cannot escape through the windows.
Temperature Rise:
The trapped heat causes the air temperature inside the car to rise significantly, often much higher than the outside temperature.
This process is similar to how greenhouses on farms work, which is why it’s called the “greenhouse effect” in the context of cars.