144MHz Warble

As I'm still fairly new to 144MHz SSB, I wonder if any of you more experienced readers can tell me about the conditions giving rise to this very obvious warble, together with the clipping of low frequencies in the voice, which persisted for a long time?

Digital signals also showed a lot of dispersion.  The auroral oval had extended to reach central Scotland at the time, but I'm not persuaded it's auroral propagation, even though it sounds like it.  The signal was from my east at the time, and beaming to the north saw the signal almost disappear, seemingly confirming it wasn't auroral (although my 8-ele is far too narrow for aurora).