Why Tropical waves

Tropical waves or Ondas Tropicais in Portuguese has two sources - the first is my love of music from the tropical regions, those are the sound waves that we all are sensitive to. What about electromagnetic waves,  they also travel around the earth and have been doing so since before we invented radio and discovered the ionosphere that surrounds the whole earth at a height of 100 Km and upwards. The space below it is an enormous resonant cavity like an electromagnetic drum, and it is being played by the thunderstorms that happen every day in local afternoon in the tropical regions.