The total eclipse of the sun on 21 August offers coast-to-coast opportunities for radio experimenters to examine diurnal propagation variations on a shortened time scale...and perhaps anomalous variations that aren't analogous to the normal day/night changes. Effects can be expected from VLF through HF (probably even at ELF), so nearly every longwave enthusiast in the US and Canada should be able to observe and document signal variations during the eclipse with their current equipment.
This will be discussed further in the August issue of The LOWDOWN.
Meanwhile, to get a sense of the potential range of experiments possible, LWCA member Rick Ferranti W6NIR suggests these Web sites as an introduction: Whitham D Reeve and HamSci.org. Rick notes that the latter is a little vague on some of the organized activities, and more can be gleaned from an addition HamSci paper on the subject.
HamSci's own effort is strictly in the HF amateur bands and employs tools like the Reverse Beacon Network and WSPRnet, the latter of which will also be useful to monitors tuned to the WSPR segments of 2200 and 630 meters. But as previously noted, all longwave buffs can get in on the action. HiFER and LowFER signals, NDBs, Navy stations monitored on SID receivers, and whistler/natural radio receivers will also all provide unique opportunities to observe the transient effects on our ionosphere of the moon's shadow. (Longwave Radio Club)