Nicholas Hall-Patch nhp at
Sat Dec 14 20:12:43 EST 2019

But doesn't the graph referenced in your link indicate that the
greatest strength from cosmic rays was 2009-2010, when trans polar
conditions were at their best, Bill?

I'd defer to K9LA's comments in a heartbeat, but isn't the one (the
primary?) reason for greater penetration of cosmic rays  the weakening
geomagnetic activity  that occurs during solar minimum, and that's related
to the intensity and speed of the solar wind, driven by coronal mass
ejections and such like.   According to, we are only now
approaching the low levels of geomagnetic activity (Ap progression chart)
seen in 2009 / 2010.    Of course we may never reach those levels.   We
have to wait and see.

best wishes,


On Sat, Dec 14, 2019 at 6:24 PM Bill Tippett <btippett at> wrote:

> This could account for relatively poor conditions on 160 despite the low SF
> and K indices:
> *COSMIC RAY UPDATE:* Something ironic is happening in Earth’s atmosphere.
> Solar activity is low–very low. Yet atmospheric radiation is heading in the
> opposite direction. Cosmic rays percolating through the air around us are
> at a 5 year high and only percentage points away from a Space Age record.
> Find out what's happening on today's edition of
> <
> >
> .
> 73,  Bill  W4ZV
> _________________
> Searchable Archives: - Topband
> Reflector

More information about the Topband mailing list