January 14, 2015:  

  1.   New analysis of Riley's "On the probability of occurrence of extreme space weather events"
  2.   Fate of "Comment" paper on Riley's submitted to  Space Weather
  3.   Lessons from this experience

1.. New analysis of Riley's "On the probability of occurrence of extreme
space weather events" (see the August 22,  and Aug. 25, 2014 entries
for background).  A link to the new analysis, entitled "A second look at
`On the probability of occurrence of extreme space weather events'",
is given at the end of this section.  In the middle of the section is a link
to the old (i.e. original) analysis.

    Riley's paper has been widely cited in the popular press as a reliable scientific
analysis showing that the probability of a crippling magnetic storm as bad as
the worst known (the so-called "Carrington event" of 1859) in a decade is
around 12%.   Riley's conclusion states:
"Our results allowed us to answer a basic question, at least in an
approximate way: How likely are [Carrington] events? ... our results
overall suggest that the likelihood of another Carrington event
ocurring within the next decade is  ~12%."
This makes it sound as if one might quibble over whether the probability were
10% or 12%, but that its order of magnitude is around  a surprisingly high 10%.  

    The popular press generally accepts this estimate uncritically as
scientifically established.  I have heard it said that it has "gone viral"
on the Internet.  Even NASA [external link] has cited this work favorably,
despite glaring flaws which the popular press might easily overlook,
but which NASA should be sufficiently expert to detect.  This has been
[external link] as an endorsement by NASA of Riley's conclusions.

    I disagree that Riley's paper demonstrates, or even convincingly motivates, 
anything close to what people seem to think it does.  Earlier I posted  
a lengthy Analysis [15-page .pdf] of Riley's reasoning along with a shorter
[3-page .pdf] summary.  The Comment was submitted to the journal
Space Weather
 which published Riley.   The next entry describes what happened
 to that submission.  

    Space weather limits its "comment" papers to 4 pages, so "Comment"
could not address  the many issues which "Analysis" did.  
The main content of "Comment" was to report that my arithmetic
obtained probability estimates (for the probability of an event
worse than Carrington in the next decade)
which were generally an order of magnitude higher than Riley's,
too high to be credible.  (Riley obtains various estimates
from various data sets under various assumptions.)

    Riley's arithmetic is based on some ambiguously reported statistics
which he calls  "MLE fits".  Before posting "Analysis" and "Comment",
I wrote him asking for clarification of the ambiguity.  He didn't reply to any
of four courteously worded inquiries about various points in the paper,
not even to a message asking for acknowledgement of receipt.
So, I had to use my best guess to resolve the ambiguities.

    Later, evidence surfaced causing me to change my original best guess.  
After that change, I was able to reproduce the results of some, but not all,
of Riley's probability estimates.  (That is not  to say that I agree that they were
convincingly derived, only that I agree with the arithmetic based on
the new best guess.)  But serious anomalies remain.
Independently, evidence surfaced of other demonstrable and
serious errors in Riley's paper.  

    Given the changes in the situation, I thought that I should revise or replace
"Analysis". The new information was so extensive and surprising that
 replacement seemed the easier choice. The replacement is titled
 "A second look [30-page .pdf] at `On the probability of occurrence of
extreme space weather events', by P. Riley".  

2. Fate of "Comment" paper submitted to Space Weather

A previous blog explained why I was submitting the "Comment" and
wondered if Space Weather would hold it for six  months or a year and
then reject it unreferreed with essentially no reason given.
(I wondered because the Journal of Physics A did that for another paper.)  
I was pleasantly surprised when Space Weather had the courtesy
not to delay for a year,  but rejected it immediately, unrefereed.  

    Here is the rejection letter .    It gives the following reasons:

"Posting of a preprint of an article via electronic media does not
[emphasis mine] constitute prior publication  ... " 
[Note added Feb. 13, 2015:   Since the Comment was rejected,
the journal's policy has been revised. Following the link
will provide the revised policy rather than the above.
The above accurately quotes the published policy at the time of rejection.]