SPORADIC E PROPAGATION, MAY 29, 1977

SPORADIC E PROPAGATION, MAY 29, 1977
Back in the days of analog television and outdoor antennas, before widespread cable TV and satellite dishes, it was not possible to pick up television stations beyond 100 miles or so away. Living in northern New Hampshire, our television reception consisted of five stations: one station each from Burlington, Vt., Poland Springs, Maine, Plattsburgh, N.Y., and two French-language stations from Sherbrooke, Que. That is except in late spring/early summer, when atmospheric conditions allowed for me to pick up sporadic ghostly images and audio of long-distant stations through something called Sporadic E Propagation. During this period, usually in late afternoon-early evening, local programming got overridden by these far distant stations.
Sporadic E occurs when intense clouds of ionisation form in the E region of the ionosphere. The level of ionisation is up to about five times that of the levels reached during the peak of a sunspot cycle when they would normally be at their highest. The high levels of ionisation resulting from Sporadic E enable VHF signals to be refracted by these ionised clouds and bounced back to earth-often at great distances.
I made these brief recordings from our family TV at 10 and 11 p.m. on May 29, 1977. These two stations were over 1,000 miles away from me: WSM Nashville, Tennessee, (station ID and brief weather); Arkansas Education Television Network (sign-off).