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Glite Dictionary
D region

D region

9.5
The lowest part of the ionosphere about 35 to 50 miles above Earth that bounces back low radio waves
  • noun
  • Specialized
translation icon : región D
  • The absorption of radio waves increases significantly in the D region during the day.

Examples

  • Within the ionosphere, the D region is especially important for long-distance communications.

  • Scientists monitor changes in the D region to understand variations in radio signal propagation.

  • The D region is crucial for radio communication.

  • Scientists study the D region to understand its effects.

  • The D region of the ionosphere plays a critical role in reflecting low-frequency radio waves used for communication.

  • Researchers have observed that the D region influences the quality of radio signals received during nighttime.

  • Understanding the behavior of the D region is essential for improving long-distance radio communications.

Synonyms

D-layer
vsD region
  • Specialized
9.5

The lowest part of the upper atmosphere high above the Earth that reflects low radio waves

is the same in meaning but uses a different common name

How High

F region
  • Specialized
8.6
E region
  • Specialized
8.1
D region
  • Specialized
9.5

Surface Forms

D region singular
D regions plural

Morphology

D + region

Although 'region' is a transparent word, the 'D' element here is an arbitrary label (a letter) with no independent lexical meaning that would signal 'lowest ionospheric layer.' The specific scientific referent of 'D region' is a conventional technical label rather than a compositionally derived meaning, so a B1 learner who only knows the parts would not be able to infer the full definition.

Etymology

D region was named when early scientists split the upper air into lettered layers and called the lowest one 'D'. Because this low layer can 'bounce' or 'absorb' 'low-frequency radio waves', the name helps explain why it 'affects' long-distance radio signals.