From Pascal.Demoulin@obspm.fr Tue May 27 17:52:44 2003
Date: Fri, 16 May 2003 10:52:51 +0200
From: Pascal Demoulin <Pascal.Demoulin@obspm.fr>
To: Jongchul Chae <chae@cnu.ac.kr>
Cc: Kanya Kusano <kusano@hiroshima-u.ac.jp>,
    'mitch Berger' <m.berger@ucl.ac.uk>,
    'Pablo Mininni' <mininni@df.uba.ar>,
    'Richard Canfield' <canfield@mithra.physics.montana.edu>,
    'Alexander Nindos' <anindos@cc.uoi.gr>, 'BC Low' <low@hao.ucar.edu>,
    'Jim Klimchuk' <james.klimchuk@nrl.navy.mil>,
    'Marcelo Lopez-Fuentes' <lopezf@nrl.navy.mil>,
    'Sarah Gibson' <sgibson@hao.ucar.edu>, sakurai@solar.mtk.nao.ac.jp,
    'Terry Forbes' <terry.forbes@unh.edu>,
    "'Brian T. Welsch'" <welsch@ssl.berkeley.edu>,
    dana@mithra.physics.montana.edu, magara@mithra.physics.montana.edu,
    apevtsov@nso.edu, haimin@sundog.caltech.edu, yjmoon@bbso.njit.edu,
    "[ISO-2022-JP] ?^[$B;3^[(B ^[$B1{L@^[(B" <yokoyama.t@eps.s.u-tokyo.ac.jp>
Subject: Re: 2 new papers on magnetic helicity

>
Dear Jongchul,


> I fully support your argument. You are the one who first clarified the
> relation between the flux density patten transport velocity and the
> plasma velocity. Attached is my own note supporting your finding, where
> I tried to make clear the definition of flux density pattern transport
> velocity. Based on your result, I will not attempt to measure the
> horizontal fields and Doppler velocity for the derivation of the
> "emergence term" in the helicity flux.

    Fine !!!    :)=

But to be honest it was first Mitch which see this point from a 
theoretical
point of view.... Mitch realized this much earlier than any attempt to 
measure the
helicity flux with the LCT method !   But this was very shortly 
mentioned in one of his
paper....and so hidden by many more interesting results !!   When the 
LCT method
started to be broadly applied it was the time to expose Mitch's results 
clearly in
the context of observations.   I remember that Kusano's paper was the 
trigger
to work this out ...and it took me some time to get fully convince by 
Mitch's
argumentation  (e.g. in the case of a growing magnetic flux..... what 
we just discuss
in previous mails !).
       After all it look a a simple result... but not so obvious to 
digest !    :)=

My best wishes,

     Pascal

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