[South Florida DX Association] ARLP001 Propagation de K7RA

[Bill Marx]

 SB PROP @ ARL $ARLP001
> ARLP001 Propagation de K7RA
> 
> ZCZC AP01
> QST de W1AW  
> Propagation Forecast Bulletin 1  ARLP001
> From Tad Cook, K7RA
> Seattle, WA  January 6, 2006
> To all radio amateurs 
> 
> SB PROP ARL ARLP001
> ARLP001 Propagation de K7RA
> 
> Average daily sunspot numbers for the past week (December 29 through
> January 4) were nearly 22 points below the previous period. Average
> daily solar flux was about the same. Average daily mid-latitude
> geomagnetic indices (A and K index) were exactly the same, and the
> planetary A and K index were slightly lower.
> 
> For the near term expect sunspot numbers and solar flux to stay
> around the same levels (low), but gradually rise to a short term
> peak around January 15-16. The A and K index should also stay quiet,
> with a returning active patch of Sun causing unsettled to active
> geomagnetic conditions around January 16 and again around January
> 23-24. January 10-12 should have very quiet, stable geomagnetic
> indicators.
> 
> Those forecasts are from the U.S. Air Force, via NOAA. Geophysical
> Institute Prague expects quiet conditions for January 9-11, quiet to
> unsettled today, January 6, and again on January 12, and unsettled
> conditions January 7-8. Currently our Sun is quiet, and the
> interplanetary magnetic field points north, both indicators of quiet
> geomagnetic conditions.
> 
> Now that we have the solar flux and sunspot numbers for all of 2005,
> it is time for a review of annual averages.
> 
> Average daily sunspot numbers for the years 1999 through 2005 were
> 136.3, 173, 170.3, 176.6, 109.2, 68.6 and 48.9. Average daily solar
> flux for the same years was 153.7, 179.6, 181.6, 179.5, 129.2, 106.6
> and 91.9. The steady decline over each calendar year since the
> 2000-2002 period should continue through the end of this year. Two
> years from now we should know when trends turned around.
> 
> David Greer, N4KZ of Frankfort, Kentucky reports more surprising
> short lived 10 meter propagation in the form of an opening toward
> Europe on December 31. Last Saturday morning he heard many strong
> European stations on 12 and 15 meters, so he went to 10 meters and
> called CQ at 1427z with his 3-element Yagi pointed toward Europe.
> I5KAP answered with a weak but readable signal. Dave reports, "Seven
> minutes later I heard F5LIW calling CQ and worked him too.  Again,
> signals were weak but readable. After we signed, he began calling CQ
> again but with no takers from what I could hear. At 1439z, I heard
> IK4GRO calling CQ. At S7, he had the strongest signal. We exchanged
> reports and he began calling CQ again but no takers from what I
> could hear. Then the signals were gone." Dave runs 100 watts on 10
> meters.
> 
> Felipe Ceglia, PY1NB of the state of Rio de Janeiro in Brazil passes
> word that he has a web site for DXers, which can be found at,
> http://www.dxwatch.com/. He carries this bulletin, along with
> spotting services.
> 
> Carl Luetzelschwab, K9LA sent in an interesting piece that he wrote
> for this week's bulletin in response to an email exchange with Red
> Haines, WO0W. It is titled "The T Index and SSNe."
> 
> Carl writes, "Due to the day-to-day variability of the ionosphere,
> our propagation prediction programs use a monthly median model of
> the ionosphere. Thus the prediction outputs (usually MUF and signal
> strength) are statistical over a month's time frame. We have a
> monthly median model, as opposed to a daily model, because the
> developers did not find a satisfactory correlation between what the
> Sun was doing on a given day and what the ionosphere was doing on
> the same day. The proper correlation was between smoothed sunspot
> number (or smoothed solar flux) and monthly median ionospheric
> parameters (foE, foF2, hmF2, etc)."
> 
> He continues, "In order to get a better picture of what the
> ionosphere is doing 'now', two similar methods have been developed:
> the T Index and SSNe. The T Index comes out of Australia's IPS
> (Ionospheric Prediction Service), and is named after its developer
> Jack Turner. SSNe (equivalent sunspot number) was developed by the
> US Air Force Global Weather Central organization, and is available
> from Northwest Research Associates. The websites are,
> http://www.ips.gov.au/HF_Systems/4/2 and,
> http://www.nwra-az.com/spawx/ssne24.html, respectively."
> 
> Carl goes on to say, "Both of these methods basically vary the
> sunspot number in a F2 region model of the ionosphere to force the
> model to a best fit to current foF2 data from worldwide ionosondes.
> Note the phrase 'best fit' - it's not a perfect fit, as the
> ionosphere does not necessarily track at all locations. For example,
> the F2 region ionization over the Millstone Hill (MA) ionosonde may
> increase at a given hour, while just 400 miles away the F2 region
> ionization over the Wallops Island (VA) ionosonde may decrease at
> the same time."
> 
> He ends by saying, "What does using the T Index and SSNe buy us?
> Neither gives us a daily model of the ionosphere due to the issue
> cited in the previous paragraph. Nor does either take into account D
> region and E region issues. But with respect to the F2 region, they
> close the gap between the heavily averaged smoothed sunspot number
> and short-term increases or decreases in sunspot activity (they also
> can show the effect of geomagnetic storms). An example of this is
> late December 2005. The official smoothed sunspot number for
> December 2005 will come in somewhere between 10 and 20, but the
> increased sunspot activity at the end of the year indicated that
> using a sunspot number of 40 in your favorite prediction program
> (from the SSNe website) would have given you a better 'now'
> prediction."
> 
> Thank you, Carl!
> 
> If you would like to make a comment or have a tip for our readers,
> email the author at, k7ra at arrl.net.
> 
> For more information concerning radio propagation and an explanation
> of the numbers used in this bulletin see the ARRL Technical
> Information Service propagation page at,
> http://www.arrl.org/tis/info/propagation.html. An archive of past
> propagation bulletins is found at, http://www.arrl.org/w1aw/prop/.
> 
> Sunspot numbers for December 29 through January 4 were 77, 67, 62,
> 41, 37, 39 and 25 with a mean of 49.7. 10.7 cm flux was 90.3, 89.9,
> 87.4, 87.4, 84.5, 84.9, and 84, with a mean of 86.9. Estimated
> planetary A indices were 8, 7, 9, 4, 5, 3 and 2 with a mean of 5.4.
> Estimated mid-latitude A indices were 7, 6, 9, 5, 5, 3 and 1, with a
> mean of 5.1.
> NNNN
> /EX
> 
>