Extra exam question E3C03
Subelement E3, RADIO WAVE PROPAGATION· Group E3C
Which of the following signal paths is most likely to experience high levels of absorption when the A- index or K-index is elevated?
- A.Transequatorial
- B.Through the auroral oval (correct answer)
- C.Sporadic-E
- D.NVIS
WhySignal paths running through the auroral oval are most likely to experience high absorption when the A-index or K-index is elevated. When the A-index or K-index is elevated, signal paths running through the auroral oval, the ring of enhanced ionization and turbulence circling the magnetic poles, experience especially heavy absorption, since that's exactly the region most directly disturbed by geomagnetic activity, answer B. Transequatorial, sporadic-E, and NVIS propagation are governed by different regions and mechanisms and aren't the paths most affected by a rising geomagnetic index.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
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