Question T3A07
From subelement T3 - T3A
What weather condition might decrease range at microwave frequencies?
Why is this correct?
Precipitation (rain, snow, ice) absorbs microwave signals, reducing their range. Water droplets are particularly effective at absorbing these high-frequency signals due to their molecular resonance characteristics. High winds, low pressure, and cold temperatures don't significantly affect microwave propagation through direct absorption mechanisms like precipitation does.
Memory tip
Remember the frequency-dependence pattern: higher frequencies are more susceptible to atmospheric absorption. Microwaves interact strongly with water molecules, while lower VHF/HF frequencies pass through precipitation relatively unaffected. This creates a clear dividing line in propagation behavior.
Learn more
Microwave absorption by precipitation demonstrates why satellite communication systems and point-to-point microwave links require link budgets that account for 'rain fade.' Commercial microwave towers often include redundancy and higher power margins specifically for heavy weather conditions. This same principle affects amateur microwave operations above 1 GHz, where operators must consider weather radar attenuation data when planning communication paths during storm systems.
Think about it
Why do you think lower frequency bands like 10 and 6 meters experience little effect from the same precipitation that significantly impacts microwave frequencies?