E layer
- noun
- Specialized
- Radio signals can travel long distances at night because they are reflected by the E layer of the ionosphere.
Examples
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The E layer is crucial for radio communications.
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Scientists study changes in the E layer to improve radio communications.
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During the experiment, the team measured ionization levels in the E layer.
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Scientists study the E layer to improve signal transmission.
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During radio broadcasts, signals can bounce off the E layer, allowing communication over long distances.
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Amateur radio operators often rely on the E layer to send messages when conditions are favorable.
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The E layer is crucial for certain radio frequencies, as it reflects waves back to Earth during the daytime.
Synonyms
Part of the upper atmosphere 50 to 90 miles above Earth that reflects medium radio waves
A layer of upper air high above the Earth that reflects medium-length radio waves
A layer high above Earth that bounces back radio waves for long-distance radio
How High
Surface Forms
Morphology
E + layer
The noun 'layer' clearly signals a stratum, so a B1 learner who knows the words would infer that 'E layer' names some kind of layer (i.e., a labeled strata). However the letter 'E' here is a technical label referring specifically to a region of the ionosphere and to radio-wave reflection — information that is not derivable from the constituents alone, so the full specialized meaning is not predictable.
Etymology
E layer got its name when early radio scientists labelled bands high in the sky with letters, and the band called E was the layer that 'bounced' medium radio waves back to Earth. So E layer now means the charged band high above the ground that helps long-distance radio.