Amateur radio operators refer to it as the ionosphere.
ki4fkw
Also doubles as cat heaven
SaintTNS
…like in Cats?
Pancakemuncher
In the 1930s a quack doctor named John Brinkley who had been stripped of his medical license in his home state of Kansas bought a radio station in Villa Acuña, Mexico called XERA and gave it a 1 million watt broadcast tower. Due to the powerful signal and this effect it could be heard in Canada on a clear night and was the first radio station that could be heard nationwide. To fill the time between pseudoscientific rants he hired The Carter Family to be his house band for a spell, introducing the nation as a whole to country music.
sprobeforebros
Hams and DX-ers used to (still?) call it “talking skip”.
Invader_Jim