Ask A Scientist© Weather Archive

name         Melissa
age          20s

Question -   Why is it that sometimes on a clear day you can hear
radio stations that are far away?

When the temperatures are right, with the atmosphere forming definite layers
of gases with smooth boundaries between the layers, radio waves can reflect
off these boundaries, bouncing back toward the earth.  This gives the radio
waves the ability to travel much farther before having to travel out into
space.
  Kenneth Mellendorf
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