Next Solar Cycle: Too bad there is not more agreement!

Next Solar Cycle: Too bad there is not more agreement!

Mild forecast for next solar cycle
http://physicsweb.org/articles/news/11/4/7/1

11 April 2007

Astronomers have long known that the Sun's "activity" rises and falls
in cycles that last roughly 11 years each. Now a team of scientists
from China and India has developed a theoretical model of solar
activity that suggests that the next cycle, which is due to begin in
about 2011, will be relatively mild. The model -- the first to confirm
predictions based purely on experimental records of solar activity --
is good news because high levels of activity can disrupt satellite
communications (Phys. Rev. Lett. 98 131101).


Scientists Predict Big Solar Cycle
http://science.nasa.gov/headlines/y2006/21dec_cycle24.htm?list89139

12.21.2006


Dec. 21, 2006: Evidence is mounting: the next solar cycle is going to
be a big one.

Solar cycle 24, due to peak in 2010 or 2011 "looks like its going to
be one of the most intense cycles since record-keeping began almost
400 years ago," says solar physicist David Hathaway of the Marshall
Space Flight Center. He and colleague Robert Wilson presented this
conclusion last week at the American Geophysical Union meeting in San
Francisco.

This link to the Hathaway/Wilson paper in the NASA 12.21.2006 news
release, "Scientists Predict Big Solar Cycle", is broken:

http://solarscience.msfc.nasa.gov/papers/hathadh/HathawayWilson2006-preprint.pdf

The published version of the paper is available at:

http://solarscience.msfc.nasa.gov/papers/hathadh/HathawayWilson2006.pdf
(151 kB)

According to the Physics Web story, the new paper by Choudhuri et al
is rebutting the paper by Dikpati et al, which used a different method
from Hathaway and Wilson. They are not rebutting the work of Hathaway
and Wilson, which agrees with the Dikpati prediction, based on a
different method.

Google turns up this unpublished rebuttal to Hathaway & Wilson, which
removes the Halloween 2003 storm events from the data used for
prediction, and gets a lower cycle 24 value:

http://members.chello.be/j.janssens/CommentsHathawayaa.pdf
(455 kB)

Another comment by Jannsens here:

http://members.chello.be/j.janssens/Engzonnecyclus.html#Activiteit24

"Most scientists do predict rather low activity for SC24. A maximum
value for R = +/- 100 (so even lower than SC23) is expected in 2011. A
complete overview of predictions on the onset and amplitude of the
next solar cycle can be found here."

That link is to these briefing charts, which in turn contain links to
sources of other predictions:

http://members.chello.be/j.janssens/SC24pred.pdf
(126 kB)

and some summary charts in HTML format:

http://members.chello.be/j.janssens/SC24.html

Links to material from Dikpati et al:

http://www.ucar.edu/news/releases/2006/sunspot.shtml

Dikpati, Toma, & Gilman, "Predicting the strength of solar cycle 24
using a flux-transport dynamo-based tool", GEOPHYSICAL RESEARCH
LETTERS, VOL. 33, L05102, doi:10.1029/2005GL025221, 2006

http://academic.evergreen.edu/z/zita/articles/Dik06GRLMar.pdf
(579 kB)

Link to FREE copy of new paper by Choudhuri et al:

http://arxiv.org/abs/astro-ph/0701527v1

http://arxiv.org/PS_cache/astro-ph/pdf/0701/0701527v1.pdf
(341 kB)

Apparently the Dikpati and Chouhuri groups have a past history of
disagreements:

http://arxiv.org/abs/astro-ph/0505232


In keeping with the spirit of Sam's original post, toss a coin?

Hope it's the latter for us Hams, been a long low.
KM