Question
What is most likely to result in auroral propagation?
Answer Options
- A) Meteor showers
- B) Quiet geomagnetic conditions
- C) Severe geomagnetic storms
- D) Extreme low-pressure areas in polar regions
Correct Answer: C
Explanation
Auroral propagation, sometimes called aurora borealis (Northern Lights) reflection, is a propagation mode primarily used on VHF and sometimes HF. It occurs when radio signals are reflected or scattered off the highly ionized curtains of gas that create the visible aurora, located at high latitudes.
These auroral curtains are formed when high-energy charged particles from the Sun collide with the Earth’s atmosphere. This process is directly caused by a highly disturbed geomagnetic field resulting from solar activity. Therefore, severe geomagnetic storms are what is most likely to result in auroral propagation. These storms are typically indicated by high K-index and A-index values on space weather reports.
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