[South Florida DX Association] ARLP015 Propagation de K7RA

[Bill Marx]

 Propagation Forecast Bulletin 15  ARLP015
> From Tad Cook, K7RA
> Seattle, WA  April 13, 2006
> To all radio amateurs 
> 
> SB PROP ARL ARLP015
> ARLP015 Propagation de K7RA
> 
> League headquarters is closed on April 14 for the Good Friday
> holiday, so the propagation bulletin arrives a day early.
> 
> Average daily sunspot numbers for the week were up over 12 points to
> 70.7. What really happened was that for the 7 days of March 30
> through April 5, the daily sunspot number at the start of the period
> was 35, and it rose to 88 by the seventh day. The next day, April 6,
> was the first day of the reporting period for this bulletin, and on
> that day the sunspot number rose to 105. The next day it had dropped
> way down to 65, then 57, then 46 last Sunday, and by Wednesday,
> April 12 it had risen again to 79.
> 
> Geomagnetic disturbances accompanied the rising solar activity. A
> solar wind stream from a coronal hole met the interplanetary
> magnetic field (IMF), which was pointing south, and this leaves
> Earth vulnerable. On April 9 the mid-latitude A index was 27 and the
> K index rose to 4 and 5. The planetary A index was 39, with the
> planetary K index reaching 5 and 6.
> 
> At 2:30 AM Seattle time on that day my cell phone received an
> automated call from Spaceweather Phone (see
> http://spaceweatherphone.com/), alerting me that "The Planetary
> K-index has reached a level of 6. This means that a moderate
> geomagnetic storm is in progress. High-latitude sky watchers should
> be alert for auroras." With this service, users can set it on a web
> interface for certain hours that it won't call (for those who are
> interested in a sound sleep). But I just have it set for 24-hour
> alerts to my wireless phone, and when the cell phone is off at night
> the alert goes to voicemail.
> 
> A similar condition to April 9 occurred four days earlier on April
> 5. But at that time sunspot 865 was still visible. This is the
> biggest sunspot seen the year, and it has since rotated out of view.
> 
> Byron Stoeser, W7SWC on April 7 wrote, "I am out on 17-meter bicycle
> mobile almost every day from my Winter QTH in Southern California.
> It has been so unexpected to go out with the high sun spot numbers
> the past two days and call CQ for 1/2 an hour with no response and
> hear very little activity on the band, while a couple of weeks ago I
> had calls from Japan, and worked the Caribbean and Europe with 0 sun
> spots. Seems to me there is a lot more to this bottom of the sun
> spot cycle than just sun spot count."
> 
> Yes, Byron is correct. Around that time he was experiencing rough
> conditions from the solar wind. Sunspot numbers were up, but so was
> geomagnetic activity on April 5.
> 
> There is a nice peppering of sunspots on the side of the Sun facing
> us, but they are small. We could see another period of geomagnetic
> disturbance this Saturday. Planetary A index predicted for the next
> few days, Thursday, April 13 through Sunday, April 16, is 10, 25, 40
> and 25. The Australian Space Weather Agency (see
> http://www.ips.gov.au/) sent an alert on Tuesday advising of a high
> speed solar wind from a coronal hole and increased geomagnetic
> activity on April 15-16.
> 
> Sunspot numbers may rise again later in the month, perhaps over 100
> again. This is most likely around April 24 through May 4.
> 
> You may sign up for their geophysical warning email alerts at,
> http://www.ips.gov.au/mailman/listinfo/ips-geo-warning. You can
> check an archive of their previous warnings at,
> http://www.ips.gov.au/pipermail/ips-geo-warning/.
> 
> Michael Mardit, WA2VQW wrote "I was in Dominica for the week
> sandwiched around the SSB-WPX and I operated mostly 30 and 17 meters
> CW (as J79VQ), while the rest of my team worked the contest. There
> is absolutely no question that operating the Grayline is the place
> to be if you want to know if anybody is out there. Sunspots or not,
> lots of DX shows up during that 'magical' 20 minutes. At other
> times, just calling CQ for a while will shake the bushes!"
> 
> Michael continues, "It seems that many Hams wait for someone else to
> initiate the call, and as such, nobody is transmitting, hence, a
> seemingly dead band. The blame is then put on the low sunspot
> activity for an empty band. Call CQ and be patient, you will be
> rewarded! VKs were calling me long path in the evening on 30 meters,
> and the JAs and UA0s were knocking on my door on 17 meters at about
> the same time. I was running 100 Watts to a vertical wire with 4
> radials on the ground. YES being DX on an island certainly helps,
> but you would never know that I was there if I didn't call CQ."
> 
> Ron Zond, K3MIY was one of several who wrote to praise the N0HR
> Propfire plug-in for the Firefox browser, which monitors solar flux
> and the A and K index when you are on the internet. WA1LOU gave
> details in his recent Surfin' column on the ARRL web site at,
> http://www.arrl.org/news/features/2006/03/31/1/.
> 
> 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 April 6 through 12 were 105, 65, 57, 46, 70, 73
> and 79 with a mean of 70.7. 10.7 cm flux was 98.9, 94.5, 91, 89.2,
> 88.7, 89.7, and 81.1, with a mean of 90.4. Estimated planetary A
> indices were 10, 3, 5, 39, 18, 5 and 2 with a mean of 11.7.
> Estimated mid-latitude A indices were 6, 2, 3, 27, 11, 3 and 1, with
> a mean of 7.6.
> NNNN
> /EX
> 
> 
>