Definition
Random electrical disturbances in the atmosphere, primarily caused by lightning discharges, that radiate radio-frequency energy and interfere with radio reception. Atmospheric noise is most pronounced at low and medium frequencies and is heard as static, crackles, or hiss in a receiver.
Plain English
The crackling and hissing sound you hear on a radio caused by lightning and other natural electrical activity in the atmosphere. It can make signals harder to hear, especially on lower-frequency radios.
Context Anchor
Encountered during radio communication, weather discussions, and any situation where thunderstorms or nearby electrical activity affect reception.
Derivation
From 'atmosphere' (Greek atmos, vapor + sphaira, sphere) and 'noise' (Old French noise, disturbance). Together it points to unwanted signals generated by the atmosphere itself rather than by equipment.
Why Pilots Care
It reduces the range and clarity of navigation and communication signals, which can force pilots to use alternate frequencies or navigation methods.
Grounding Statement
Picture trying to hear a quiet voice on the radio while distant lightning adds sharp crackles over the top of it.
Intuition Check
Atmospheric noise does not mean normal cockpit noise or engine sound. Here, it means radio interference caused by natural electrical activity in the atmosphere.
Example Sentence 1
As the flight neared the line of thunderstorms, atmospheric noise made the NDB signal almost unreadable.
Example Sentence 2
Atmospheric noise made the distant VOR station unreadable, so the crew tuned to a closer one.