Your Ionosphere In Action

WWV

Unless you're a member of the small group of science people who specialize in atmospheric science, space weather, or metrology, you're probably not too familiar* with how the sun affects the ionosphere, which in turn changes its radio-reflective properties. And, I'm guessing, you have never tried to measure those properties over an extended period. Another guess: Even if you are one of the science people mentioned, you probably didn't participate in the June 2021 Arctic Eclipse Festival. How sad!

Radio Station WWV, unlike the AM or FM broadcast stations to which you listened before "streaming" took over, can be slightly more monotonous**. It has a voice announcing the time every minute with electronic tones and clicks that allow one to synchronize clocks and other instruments. Through the blessing of hyperlinks, you can find out vastly more than I can write (or know) by minimal clickage. WWV broadcasts on several precise frequencies. In fact, disregarding certain quantum niceties, they are the very definition of frequency, since they are run by what used to be called the Bureau of Standards.

Research!

Despite my running disclaimer of research for this blog, this is research, and it doesn't vitiate my disclaimer since I didn't do it for the blog, but rather for the festival mentioned above. The graphs represent the frequency and amplitude of WWV as received about 500 miles southwest of the transmitter. The WWV frequency is fixed and precise, and my receiving equipment, which uses GPS as a frequency standard, is essentially perfect as well. Any deviation from a straight horizontal line represents the effect of the ionosphere, whose properties vary throughout the day due to various consequences of the rotation of the earth along with radiation and particles from the sun and space. One purpose of these measurements was to determine the ionospheric effects of a solar eclipse, which was scheduled during the Festival.

Measured WWV Frequency and Amplitude vs. 24-hour time. First four graphs are at 5MHz, bottom left is 10MHz, and bottom right is 15MHz.

Science can be pretty, no? But these are shrunken graphs. The real ones, along with tabular data and more details on how they were created, are here. (If you like my graphs, here's one of Prius battery voltage.)

* OK. Not familiar at all.

** Monotonous to some. I've been listening to WWV for about 65 years, albeit not continuously. I find it a constant, comforting companion in an uncertain world. Does this surprise you?

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