E layer
1
9.6
- 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
1
9.1
A layer high above Earth that bounces back radio waves for long-distance radio
1
8.1
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
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.