Topband: FW: wwv

Roy Morgan roy.morgan at
Tue Nov 7 09:51:35 EST 2006

At 08:16 PM 11/6/2006, Gary Nichols wrote:
>I had inquired as to what the "R" in the WWV report was and never got an
>answer so I asked K9LA and this was his reply:
>what exactly does the "R" number in the 3-hourly wwv report mean? ...
>There are two "Rs" in propagation reports.
>The first use of R is tied to disturbances to propagation. This R is on a
>scale of 1 to 5, ...
>The second use of R is the daily sunspot number. Your question about R = 62
>was this use of R.

Hello from NIST, the parent organization of the WWV facility,

I refer you to:

NIST Special Publication 432, "NIST Time and Frequency Services", 2002 
Edition.  This can be had at:

Document numbered page 41, PDF document page the section titled "Gephysical 
Alerts", which describes in non physicist terms what this is all about. I 

"Space weather storms observed or expected to occur are characterized using 
the NOAA Space Weather scales. ... These space weather scales are described 
in more detail on the NOAA Space Environment Center's
web site ("

One of the scales is the R-1 to R-5 scale, called "Radio Blackout".  I do 
not see in this report any mention of Daily Sunspot Number.  Also, a quick 
check of the NOAA site above turns up this at:
"The official International Sunspot Number (RI) is issued by the Sunspot
Index Data Center (SIDC) in Brussels.  Data and plots are available from
the SIDC web site at  "
There you can see graphs and data of the "Smoothed Sunspot Number" that 
they refer to in at least one graph as "Ri".

By the way,
  - The NIST document above contains a nice picture of the WWVB 
transmitter(s).  Please move back from your keyboard lest any drooling get 
into the keys.
  - A series of "Time Exhibits" about many facets of time and time keeping 
can be seen by starting at where you can get the 
correct time, and clicking the "Time Exhibits" link:
  - The home page for all this is 
and it contains lots of interesting links and references.


- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing
13033 Downey Mill Road, Lovettsville, VA 20180
Phone 540-822-5911   Cell 301-928-7794
Work: Voice: 301-975-3254,  Fax: 301-975-6097
roy.morgan at --  

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