Re: (Tor Dot Com) Speculative Extrapolation

Robert Carnegie  <rja.carnegie@gmail.com> wrote:

>
What is current news about the observed
weakening of Earth's magnetic field?
I write as a concerned resident.

The earth's magnetic field is a consequence of charges from the sun causing
currents in the liquid core, and the rotation of the liquid core which
results from the spin of the earth.

Nobody is really sure why the core current gets disrupted now and then and
how the core dynamo goes wrong, but when this happens, it's possible for
the dynamo to restart with opposite current flow and the theory is that
this is what happens to cause those reversals.

But nobody really knows the core structure or exactly what the physical
movement of fluid actually is like, because we can't actually get down
there to look.  So our knowledge of the core is pretty incomplete and nobody
really has the ability to predict what is going to happen with the field
long term.

Glatzmaier and Roberts wrote an article in Nature back in 1995 called
"Three-Dimensional Self-Consistent Computer Simulation of a Geomagnetic
Field Reversal" and then a year later wrote a paper in Science called
"Rotation and Magnetism in the Earth's Inner Core" and these are interesting
because they basically show a simulated core flow and how it can be made
to behave like the earth's actual field, but without any real justification
that the physical structure is anything like the simulation.  But that is
about as good as it gets.

However, if you are willing to live with predictions for the next three
days, THOSE can be supplied pretty easily at https://www.solarham.net/geo_forecast.htm

I think they said that Venus has an
external magnetic field, due to the
"solar wind" diligently stripping
atmosphere from the planet, so do we
have that to look,forward to?  I won't
say to hold our breath.  :-)

Yes, venus has a crazy ionosphere that is super dense and at very low
altitudes on the day side, while the night side ionization is nearly
nonexistent.  Makes radio propagation very interesting, especially
"grayline" propagation over the magnetopause which must be very different
than grayline on earth.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."