Polar Eclipse Update

Now that the eclipse is over, here is an update on what we observed. The trans polar HF propagation didn't seem to be effected very much. One would expect a reduction in bottom side electron density. How this is seen in a small incidence angle radio wave propagation is not entirely obvious. Here is a plot of the signal-to-noise ratio as a function of time for two days before the eclipse, and the day of the eclipse. I have marked the time of the Eclipse with a red vertical line. While there is a brief period with lower signal after the eclipse, it doesn't look extraordinary. Transpolar propagation is periodically disrupted by energetic precipitation related absorption,

Signal-to-noise ratio as a function of time and frequency for the transpolar HAARP-Skibotn propagation path. Nothing extraordinary appears to happen. This is probably due to the very small incidence angle of propagation. The time of the eclipse is shown with a vertical red line.

 

 

The EISCAT radars in Svalbard and Tromsø did observe clear effects, such as a decrease in bottom-side electron density and electron temperature.