The atmosphere affects the propagation of electromagnetic waves in several ways, depending on the wave’s frequency and wavelength. Here’s how:
1. Absorption
- Certain gases like oxygen, water vapor, and carbon dioxide absorb specific frequencies.
- Infrared and ultraviolet waves are partially absorbed by water vapor and ozone.
- Gamma rays and X-rays are almost completely absorbed by the upper atmosphere.
2. Scattering
- Shorter wavelengths (like ultraviolet and blue visible light) scatter more in the atmosphere.
- This causes phenomena like the blue sky and red sunsets.
3. Reflection and Refraction
- Layers of the atmosphere, especially the ionosphere, can reflect or bend radio waves.
- This allows long-distance radio communication by bouncing waves between the Earth and the ionosphere.
4. Attenuation
- Rain, fog, and clouds can weaken signals, especially microwaves and millimeter waves, used in satellite and radar systems.
5. Delay and Distortion
- Variations in atmospheric pressure and temperature can cause signal delay or distortion, especially in GPS and satellite communication.