[meteorite-list] Meteorites Used To Study Solar Activity AT LAST!!!

From: K. Ohtsuka <ohtsuka_at_meteoritecentral.com>
Date: Thu Sep 28 07:58:06 2006
Message-ID: <000c01c6e2f4$e661bb20$627e76da_at_LocalHost>

Hello list members,

see the following link,

http://www.aanda.org/index.php?option=com_content&task=view&id=181&Itemid=42&lang=en

where you can download the PDF file of the A&A letter.

Katsuhito O.
Tokyo, JAPAN


----- Original Message -----
From: "Rob McCafferty" <rob_mccafferty_at_yahoo.com>
To: <meteorite-list_at_meteoritecentral.com>
Sent: Thursday, September 28, 2006 7:00 AM
Subject: [meteorite-list] Meteorites Used To Study Solar Activity AT LAST!!!


> Hi all
>
> This phenomena of cosmic ray alteration of isotope
> concentration has been known to me for a long while.
>
> As solar activity increases, it deflects the cosmic
> rays which reduces the effect of cosmic rays.
>
> On earth, one of it's best effects is altering the
> amount of Carbon 14 (C14) prodced during periods of
> high solar activity. C14 has a known half-life of
> approx 5800 years and is created constantly so all
> things once living have a known amount of it. Once
> they die, this proportion decreases.
>
> Less well known is that year on year, the proportion
> of C12/C14 changes according to solar activity.
> Correction factors have to be made in carbon dating.
>
> Individual tree rings can be measured for actual vs
> predicted C12/C14 ratios and a picture of solar
> activity can be build up.
>
> This method shows several things
>
> Tree rings from 1640 to 1710 show a big increase in
> C14 vs predicted signifying a low solar activity. This
> roughly corresponds to a period of low temperature.
> The Thames in London used to freeze each winter and
> was so thick fairs could be held on the ice.
>
> It suggests that in Roman times, temperatures were
> even warmer than today. Grapes can only be grown in
> south east England today. Back then they could be
> grown North of York.
>
> It also suggests a general increase in solar activity
> over the last few hundred years, since the Maunder
> minimum, in fact. We're on a rise now, apparently.
>
> If meteorites are also showing this trend, some
> credence must be give to the "The Human Race is a
> bunch of arrogant idiots who think they are more
> influential in the Grand Scheme of Things than they
> really are" school of thought which I aspire to
> ascribe.
>
> Equally, I suggest that this blip in the epochs of
> time should be a timely reminder not to mess with
> things too much as we really have no idea how much
> influence we really have.
>
> Just my thoughts for the subject.
>
> (DISCLAIMER: this post was not sponsored by
> Shell/BP/XXon/FINA/Texaco or any other petrolium
> industry, etc. The author cannot discount the
> possibility that the original meteorite study may have
> been. He would like to distance himself from any
> suggestions to that effect....
>
> I think that puts me in the clear)
>
> Anon (just in case)
>
>
>
> --- "Matson, Robert" <ROBERT.D.MATSON_at_saic.com> wrote:
>
> > Hi All,
> >
> > Who'da thunk that global warming could become an
> > on-topic
> > subject for the meteorite list?! --Rob
> >
> > -----Original Message-----
> > From: meteorite-list-bounces_at_meteoritecentral.com
> > [mailto:meteorite-list-bounces_at_meteoritecentral.com]
> > On Behalf Of Ron
> > Baalke
> > Sent: Tuesday, September 26, 2006 2:15 PM
> > To: Meteorite Mailing List
> > Subject: [meteorite-list] Meteorites Used To Study
> > Solar Activity
> >
> >
> http://www.upi.com/NewsTrack/view.php?StoryID=20060926-015940-3936r
> >
> > Meteorites used to study solar activity
> > UPI
> > September 26, 2006
> >
> > OULU, Finland (UPI) -- A Finnish-led international
> > team has used
> > meteorites to investigate the sun's solar activity
> > of past centuries.
> >
> > Ilya Usoskin at Finland's Sodankyla Geophysical
> > Observatory and
> > colleagues compared the amount of Titanium 44 in 19
> > meteorites that have
> > fallen to the Earth the past 240 years. They said
> > their findings confirm
> > that solar activity increased strongly during the
> > 20th century. They
> > also find the sun has been particularly active
> > during the past few
> > decades.
> >
> > The scientists say studying the sun's activity is
> > one of the oldest
> > astrophysical projects, as astronomers began
> > recording the number of
> > sunspots to trace the sun's magnetic activity 400
> > years ago.
> >
> > The team examined a set of 19 meteorites whose dates
> > of fall are
> > precisely known, measuring the amount of radioactive
> > isotope Titanium 44
> > in each meteorite. Titanium 44 is produced by the
> > cosmic rays in the
> > meteorites while they are outside the Earth's
> > atmosphere. After the
> > meteorite has fallen, it stops producing the
> > isotope.
> >
> > By measuring the Titanium 44 in the meteorites, the
> > scientists
> > determined the level of solar activity at the time
> > the meteorite fell.
> >
> > The study appears in the journal Astronomy &
> > Astrophysics Letters.
> > ______________________________________________
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> > Meteorite-list_at_meteoritecentral.com
> >
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> >
>
>
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Received on Thu 28 Sep 2006 07:54:48 AM PDT