Hi,
I sent this two days ago but I never got it back and it didn't show up on
the archive so I will try again. I am in the middle of an exchange over
young earth evidences and one that I have been asked to respond to is the
question of the amount of helium in the atmosphere. Well, I am quite aware
of the typical arguments and responses but this person has included what he
says is more current information. Not knowing the status of
ionosphere/upper atmosphere research and this person being a physics Ph.D I
am not sure how to respond to what he is saying her. I am hoping someone
out there has more current information than the 1969 estimate of helium
escape from the upper atmosphere the usual response depends upon. I have
to admit I don't feel comfortable always falling back on just this one
estimate of helium loss. Any advice would be greatly appreciated.
Joel Duff
Here is the relevent portion of the e-mail I wish to respond to:
"+ Long agers have suggested that there must be a continual leakage of He4
out of our atmosphere. I've been doing simulations for 4 years and find
that ionospheric escape of He4 is very rare; in fact, I would be very
surprised if someone could tell me how it is possible that millions of
tons of uncharged particles can escape the atmosphere. Lighter *charged*
particles like H+ can escape more easily. Even He+,++ and O+, though
rare, can apparently escape. The dominant ionospheric source for the
terrestrial magnetosphere filling is H+ (and protons). That being said,
there is observation of heavy ions in the earth's magnetotail, near and
distant, but it is associated with parallel to the magnetic field
potential drops during magnetospheric substorms (e.g. Seki's paper in
Substorms-4, Kluwer, Dordrecht, 1998, p/417). For He4 to escape our
atmosphere requires a source of ionisation (such as during substorms
where electrons and protons cause ionisation in the upper atmosphere.
It would have to be a very special substorm, and even a very large
magnetospheric storm, before these magnetospheric particles can reach so
deep into our atmosphere that they are able to cause mass charging of
neutral He. Then the newly ionised He++ still has to be sucked out.... Am
I supposed to believe in miracles!?"
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