The display was so bright (maximum on the 1-5 scale), that people were stopping their cars and getting out to have a look. Without doubt, this was one of the brightest, if not the brightest and densest I have ever seen in 20+ years of observing.
So extensively was the display seen that this morning's BBC news was even carrying stories about it.
As the sun descended and the display became dimmer, I spent a few minutes sending transmissions at 24MHz on a beam heading of 30 degrees. Although it wasn't necessarily linked to the NLC or associated PMSE, I was surprised to find these reports coming back at between 23:47 and 23:54UT:
What made me wonder about the possible role of goings-on in the mesosphere was the fact that, after 23:54UT, despite transmitting every 30 seconds until about 00:05UT, I was not heard again.
It's very possible (i.e not certain) that the transient reception reports were due to reflections by wave structures, which were present in abundance in this display. Indeed, the entire display was probably the result of a localised upward energy transport and wave breaking in the mesosphere, because just two hours later, as we moved into the morning sector in Wales, the NLC display had disappeared entirely.
Because the waves move very fast (anything from ~80-400m/s), this can explain temporary propagation effects.
After writing this post, I discovered PA0K had a superb image to show, and PE4BAS had even more interesting events to report up at 50MHz.
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| Close-up of gravity waves breaking in the mesosphere last night. |
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