[SFDXA] ARLP029 Propagation de K7RA

[Bill]

> SB PROP @ ARL $ARLP029
> ARLP029 Propagation de K7RA
> 
> ZCZC AP29
> QST de W1AW  
> Propagation Forecast Bulletin 29  ARLP029
> From Tad Cook, K7RA
> Seattle, WA  July 18, 2014
> To all radio amateurs 
> 
> SB PROP ARL ARLP029
> ARLP029 Propagation de K7RA
> 
> Solar activity is suddenly weakening, and yesterday, Thursday, July
> 17 the daily sunspot number was zero. We had no other zero sunspot
> days so far this year, none last year or in 2012, and only two in
> 2011, on January 27 and August 14.
> 
> We had 48 days with a sunspot number of zero in 2010 (although
> Spaceweather.com reports 51 days, and they may be correct), and 260
> days with a daily sunspot number of zero in 2009. 2008 had 239
> spotless days, and 2007 had 152 days with zero sunspots.
> 
> Just to revisit the deep trough of solar inactivity we emerged from
> a few years ago, 2006 had 70 spotless days, 2005 had just 17 days
> with no spots and 2004 saw only four spotless days. Prior to that we
> have to look way back to the twentieth century to 1998 to find any
> spotless days, (three) and 1997 had 57 days with zero sunspots.
> 
> We have not seen any new sunspot regions emerge since July 10 and
> 11, when there was a new one each day. On July 8 two new regions
> appeared. Prior to that we saw a new sunspot region appear each day,
> from July 1 to 6.
> 
> The short term outlook for solar flux shows a flux value of 90 on
> July 18 to 21, 95 on July 22 to 24, then 105, 115, 125, 135 and 140
> on July 25 to 29, 145 on July 30 and 31, then it peaks at 155 on
> August 2, then drops to a minimum of 95 again on August 16 and 17.
> 
> The same forecast shows planetary A index of 5 on July 18 to 20, 8
> on July 21 and 22, 5 on July 23, 8 on July 24, 5 on July 25, 8 on
> July 26, and 5 again on July 27 through August 9.
> 
> The average daily sunspot number for the recent seven-day reporting
> period (July 10 to 16) was only 96.9, down from 205.1 for the
> previous seven days. The solar flux average was 131.1, down from
> 193.9 a week ago.
> 
> OK1HH predicts the geomagnetic field will be quiet on July 18 and
> 19, mostly quiet July 20, quiet to active July 21, mostly quiet July
> 22, quiet to active July 23, mostly quiet July 24, quiet on July 25,
> mostly quiet July 26, quiet to unsettled July 27, quiet July 28 and
> 29, quiet to unsettled July 30 and 31, quiet on August 1, quiet to
> active August 2 and 3, mostly quiet August 4 and 5, quiet to
> unsettled August 6 to 9, quiet to active August 10 and 11, mostly
> quiet August 12, and quiet again on August 13.
> 
> Pete Corp, K2ARM of Fort Edward, New York wrote on July 11, "I wrote
> last on July 1 and since then you must have had a lot of reports of
> great propagation on 6 and 2 meters. 6 meters has been open every
> day and some days for 12 hours or more. I was able to work a couple
> of new countries, on July 5 EA8DBM and EA8TL then on July 6 XE1AY. I
> have been hearing many Mexican and California stations but could
> never break the pile ups before and they also seem to be beaming JA
> but I can still hear them. Conditions are much better and some days
> it is hard to find a spot to call CQ on 6 meter CW."
> 
> Jon Jones, N0JK has some interesting comments regarding the question
> of 6 meter sporadic-e vs.  F2 layer propagation in recent bulletins.
> Jon wrote, "Agree it was multi-hop sporadic E, possibly with some
> chordal Es hops which would reduce signal loss as opposed to F2. Due
> to seasonal characteristics of the F-layer, F2 is almost impossible
> on 6 meters in the northern hemisphere during the summer despite
> high solar fluxes.
> 
> EA8DBM did have an amazing signal. I worked Alex on 50.101 MHz July
> 5 at 1520z from my mobile in EM28. Solid Q-5 CW signal with a whip
> and 100 watts. Alex made many 6 meter contacts in North America.
> 
> The trans-Pacific tropo duct was also open July 5/6 from Hawaii to
> California. KH7Y made the trip up to the 8,000 foot level on Mona
> Loa and made numerous 144, 222 and 432 MHz contacts along the
> California coast."
> 
> Emil Pocock, W3EP of Lebanon, Connecticut wrote on July 13, "Ten
> meters opened to Europe by 6:00 AM local time (1000 UTC) here in
> Connecticut for the IARU Contest and stayed opening to the contest's
> end at 1200 UTC. This was quite unusual, given the season, SFI, and
> time of day. This unexpected opening was probably not via the usual
> F2 propagation, but more likely sporadic-E. A few 6-meter contacts
> were reported from W1, 2, and 3 to CT, I, and 4X about the same
> time, almost certainly sporadic-E. On 10 meters, I worked from G, F,
> and EA east to HA, 9A, and S5. I had the impression the opening was
> quite limited in geographical extent on both ends of the US-Europe
> path."
> 
> Randy Crews, W7TJ has some interesting observations about cycle 24
> and where we go from here.
> 
> "http://www.stce.be/newsletter/images/2013/19SolarCycleFC2.png
> clearly shows how cycle 24 compares relative to other cycles. Note
> that we are at the 72 Month mark, 6 years into this cycle.  Looking
> at other cycles, it's easy to see cycle 24 is reaching the end point
> as other cycles have done. Additionally, if a cycle starts weak (as
> cycle 24 did) it will finish weak - thus far holding true to
> history. Speaking of starting weak, it took cycle 24 two and one
> half years from the bottom in late 2008 until the solar flux climbed
> above 100 (February, 2011) typically the average time for this to
> happen is 12 months. This was the first time the solar flux reached
> 100 since 2005!
> 
> Here is a graph of the weak cycles, 24 of course included:
> 
> http://www.solen.info/solar/images/comparison_similar_cycles.png
> 
> This cycle may not be as week as cycle 14, but currently it is
> running close to cycles 16 and 12.
> 
> See http://k9la.us/A_Look_at_All_Twenty_Three_Solar_Cycles.pdf
> 
> This shows a nice bar graph of all cycles up to 24 provided by K9LA.
> Clusters of high and low cycles trend together in larger macro
> cycles of 40 to 50 years. Fitting a trend line to the graph, we are
> definitely on a downward trend with regard to the big picture, but
> also the near term outlook.
> 
> Reference the graph on page 4 at:
> 
> http://www.swpc.noaa.gov/weekly/pdf/prf2027.pdf
> 
> Notice the wide variation between monthly highs and lows. (Solar
> Flux Values of 200+ and mid-90s all within a 30 day period.) This is
> also typical of a cycle reaching the end of its max point - wide
> monthly fluctuations from min to max where it previously varied
> maybe 1/3 of the range.  (Cycle 22 had a 160 point monthly variation
> in January of 1991, with solar flux ranging from 200 to 360.)
> 
> Cycle 24 had a brief peak in November of 2011, then was flat until
> October 2013 when the average monthly solar flux steadily climbed
> month after month, reaching average monthly peak of 170 in February
> of this year, then declining every month consistently thru June of
> this year.
> 
> How much of a bounce back we have in July and subsequent months will
> really depend on not only the number of monthly sunspots, but also
> their magnetic size and complexity, which this year has been
> absolutely key to cycle 24's second peak, and it's usurping the
> November 2011 highs.
> 
> Conclusion: The peak of this cycle 24 will go down to be February of
> 2014 as all the aforementioned data confirms. We may find cycle 24
> giving a last hurrah this fall, but it would be strictly gratis and
> on borrowed time.
> 
> Livingston and Penn have it right. If the size and magnetic strength
> of sunspots resumes its downward trend, we will indeed have a
> "Propagation Winter" and cycle 25 will be even lower.
> 
> Also keep in mind referencing the first graph (of the weak cycles)
> we will have considerably lower highs from which to fall from this
> cycle compared to cycles 21, 22, and 23. (cycle 23 took 5 years,
> 2001 to 2006, before we entered the low portion of the cycle with
> solar flux values of 70 to 80. With cycle 24, the fall could
> materialize as quickly as it began in October 2013. It will be real
> interesting to see how all this plays out."
> 
> For more information concerning radio propagation, see the ARRL
> Technical Information Service at
> http://arrl.org/propagation-of-rf-signals. For an explanation of the
> numbers used in this bulletin, see
> http://arrl.org/the-sun-the-earth-the-ionosphere. An archive of past
> propagation bulletins is at
> http://arrl.org/w1aw-bulletins-archive-propagation. More good
> information and tutorials on propagation are at http://k9la.us/.
> 
> Monthly propagation charts between four USA regions and twelve
> overseas locations are at http://arrl.org/propagation.
> 
> Instructions for starting or ending email distribution of ARRL
> bulletins are at http://arrl.org/bulletins.
> 
> Sunspot numbers for July 10 through 16 were 159, 166, 145, 102, 70,
> 25, and 11, with a mean of 96.9. 10.7 cm flux was 177.4, 166.3, 145,
> 126.8, 109.4, 100.6, and 92.1, with a mean of 131.1.  Estimated
> planetary A indices were 8, 6, 6, 5, 9, 7, and 5, with a mean of
> 6.6. Estimated mid-latitude A indices were 11, 7, 7, 6, 10, 10, and
> 5, with a mean of 8.
> NNNN
> /EX