[SFDXA] ARLP030 Propagation de K7RA

Fri Jul 22 18:52:24 EDT 2016

> SB PROP @ ARL $ARLP030
> ARLP030 Propagation de K7RA
> 
> ZCZC AP30
> QST de W1AW  
> Propagation Forecast Bulletin 30  ARLP030
> From Tad Cook, K7RA
> Seattle, WA  July 22, 2016
> To all radio amateurs 
> 
> SB PROP ARL ARLP030
> ARLP030 Propagation de K7RA
> 
> All solar indices rose over the past week, and geomagnetic
> indicators were lower.
> 
> Average daily solar flux rose from the previous seven days at 52.6
> to 58.1, and average daily sunspot numbers rose from 91.6 to 103.6.
> 
> Average daily planetary A index went from 15.7 to 10.6 and average
> daily mid-latitude A index changed from 14.1 to 11.1.
> 
> The latest (Thursday night) predictions for solar flux show 100 on
> July 22 to 23, 95 and 90 on July 24 and 25, 85 on July 26 and 27, 80
> and 75 on July 28 and 29, 70 on July 30 to August 4, 80 and 95 on
> August 5 and 6, 105 on August 7 to 16, 100 on August 17 and 18, then
> 95, 90, 80 and 75 on August 19 to 22, and 70 on August 23 to 31.  For
> the next few days following the end of August the prediction shows a
> sharp rise in solar flux from 70 to 105.
> 
> Predicted planetary A index levels are at 10, 8, 12, 8 and 5 on July
> 22 to 26, 8 on July 27 to 31, 5 on August 1 and 2, 20 on August 3
> and 4, 15 on August 5, 10 on August 6 and 7, then 20, 8, 12, 10 and
> 8 on August 8 to 12, 5 on August 13 and 14, then 8, 12 and 15 on
> August 15 to 17, 10 on August 18 and 19, 8 on August 20, 5 on August
> 21 to 23, then 8 and 9 on August 24 and 25, 8 on August 26 and 27, 5
> on August 28 and 29, and 20 on August 30 and 31.
> 
> At 2341 UTC on July 19 the Australian Space Forecast Centre issued a
> geomagnetic disturbance warning:
> 
> A shock wave signature was detected in the solar wind on 19 July at
> 2300 UTC.  A geomagnetic sudden impulse is expected, followed by
> increased geomagnetic activity up to minor storm levels.
> 
> INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL MASS EJECTION
> FROM 20-22 JULY 2016
> 
> GEOMAGNETIC ACTIVITY FORECAST 
> 20 Jul:  Active to Minor Storm 
> 21 Jul:  Active 
> 22 Jul:  Unsettled to Active
> 
> The Geomagnetic activity forecast for the period July 22 to August
> 16, 2016 from OK1HH follows.
> 
> Geomagnetic field will be: 
> Quiet on August 1, 13 and 14 
> Mostly quiet on July 25, 28 and 29, August 11 and 12 
> Quiet to unsettled on July 26, August 7, 16 
> Quiet to active on July 22, 27, 30 and 31, August 2, 5 and 6, 8 and
> 9, 10, 15
> Active to disturbed on July 23 or 24, August 3 and 4
> 
> Increased solar wind from coronal holes is expected on July 27 and
> 28, July 30 through August 2, and August 7 and 8.
> 
> Bob Sherman, K2SJP of Lutz, Florida noted a 10 meter opening on July
> 11 when he worked many West Coast stations.  The next day on 10
> meters he worked a station in Kuwait.
> 
> Dave Grubbs, N4EF of Apopka, Florida wrote, "You wrote in
> Propagation Forecast Bulletin 29 that any perking up of propagation
> would be unpredictable and temporary -- how right you were.
> 
> There was a fleeting 30 minute night-time opening from my central
> Florida QTH on 30 meters on July 17.  The band was dead at 0745 UTC
> (3:45 AM EDT) and there were no replies to my CQs on 10112 KHz.
> About 15 minutes later, I copied a GI4 station, JA1KIH, and CO8LY at
> the same time within 500 Hz of each other.
> 
> The GI4 was engaged in a QSO and the JA1 and CO8 were calling CQ
> simultaneously nearly on top of each other.  I worked Taka, JA1KIH
> with a 559 report each way which was thrilling since I was running
> 100 watts to a dipole 15 feet high in my attic.  The Cuban station
> was loud enough to cause QRM to my QSO yet Eduardo is only 700 miles
> (1113 km) from me and had a steady signal.  Was this a very short
> skywave hop or a long groundwave signal from Cuba?
> 
> My Florida QTH and Taka's QTH appear to be in the gray line at the
> same time, but this brief opening occurred at 0800 UTC which was 2
> hours 39 minutes before my sunrise and hence not attributable to
> terminator/gray line propagation.  The band was void of CW again
> until well past sunrise."
> 
> Check out Dave's interesting post and images on his call sign listing
> on QRZ.com: https://www.qrz.com/db/n4ef
> 
> Actually what I was trying to say in last week's bulletin was any
> increase in solar activity would be temporary.
> 
> Ted Leaf, K6HI in Kona, Hawaii asked "What is the correlation
> between sunspot numbers and solar flux?"
> 
> There is a high correlation between sunspot numbers and solar flux,
> assuming you are looking at smoothed values for each.  Smoothed
> sunspot numbers average a year of data, so the actual value lags
> behind the latest data by six months.
> 
> Here is an article by K9LA on the topic:
> 
> http://k9la.us/Correlation_Between_Solar_Flux_and_Sunspot_Number.pdf
> 
> Determining the sunspot number is somewhat subjective, and it is
> also tough to do when the sky is overcast.  But the 10.7 cm solar
> flux is completely objective.  It involves pointing a parabolic dish
> at the sun at local noon, then measuring the radiation at 2.8 GHz.
> 
> This paper notes a correlation which also incorporates solar
> irradiance:
> 
> https://arxiv.org/ftp/arxiv/papers/0804/0804.1941.pdf
> 
> Interesting article about our sun in a recent issue of The Atlantic:
> 
> http://www.theatlantic.com/science/archive/2016/07/staring-at-the-sun/491939/
> 
> Jeff, N8II in West Virginia reported on July 16:
> 
> "Some of your readers should have experienced 2M Es on Friday
> evening (July 15) around 0000-0100Z.  DXMAPS.com showed estimated
> MUF's as high as over 180 MHz over grids in eastern OH, NW PA, and
> western NY.  I worked as close as EN91 on 6M and many stations
> centered around Chicago extending eastward including IN and OH both
> in EM79.  NP4A was also worked and the evening before I logged 3 or 4
> Puerto Rico hams on 6M phone and CW all in FK68.
> 
> Despite the improved SFI, 15 M remains very dead sounding, but I
> have not had time to listen much since the IARU contest last
> Saturday July 9 when EU signals were mostly weak and from south EU,
> but I did work around 50 of them along with some Es into New England
> and quite a few Caribbean and SA stations."
> 
> 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 14 through 20 were 54, 73, 47, 51, 68, 58,
> and 56, with a mean of 58.1.  10.7 cm flux was 95.1, 102.1, 106.6,
> 105.2, 107.1, 100.8, and 108, with a mean of 103.6.  Estimated
> planetary A indices were 12, 11, 8, 6, 4, 10, and 23, with a mean of
> 10.6. Estimated mid-latitude A indices were 16, 10, 8, 10, 4, 11,
> and 19 with a mean of 11.1.
> NNNN
> /EX