Propagation de K7RA
16 June, 2018Sunspots returned a few days ago after a 7-day absence. Average daily sunspot number dropped from 12.9 in last week's report to 4 this week. Average daily solar flux dropped from 73.2 to 69.4.
Geomagnetic conditions were quieter with average daily planetary A index declining from 11.7 to 4.4 and mid-latitude A index from 10.4 to 5.1.
Predicted solar flux is 72 on June 15-21, 75 on June 22-23, 74 on June 24-25, 73 on June 26, 72 on June 27-28, 71 on June 29-30, 70 on July 1-3, 69 on July 4-6, 70 on July 7, 72 on July 8-14, 73 on July 15, 74 on July 16-17, 75 on July 18-20, 74 on July 21-22, 73 on July 23, 72 on July 24-25, 71 on July 26-27 and 70 on July 28-29.
Predicted planetary A index is 5 on June 15-26, then 15, 28, 18 and 10 on June 27-30, 5 on July 1-8, 8 on July 9-11, 5 on July 12-15, 8 on July 16, 5 on July 17-23, then 15, 25, 15, 8 on July 24-27 and 5 on July 28-29.
Next weekend is ARRL Field Day, June 23-24. Predicted planetary A index of 5 on both days is a welcome indicator of undisturbed conditions, as are the predicted solar flux values of 75 and 74.
The latest from Dr. Tamitha Skov:
"Dear Tad,
"Have I ever mentioned forecasting Space Weather is hard? One would think that with all the spacecraft and instruments we have trained on the Sun, we would be able to do so much better than we do. This week is a perfect example of that. Just eight and a half days ahead of us (in terms of weather that is) sits the STEREO-A spacecraft. It sees solar features before we do at Earth and gets to sample the solar wind created by these features on the Sun a little more than a week before we do. Watching data from STEREO-A is a great way to know what is coming. Except when it doesn't.
"This is of those times. Though STEREO-A gives us a great look into the future, I must constantly remind myself how quickly things change on the Sun. The coronal hole that was open just 8 days ago, likely closed up a bit as it rotated to the Earth-strike zone. Not only that, but right now, STEREO-A is about six degrees further south in solar latitude than is Earth. Obviously, in this case that makes a huge difference.
"So this week, we are only being brushed by a fast wind stream that is flowing mostly south of Earth. I had hoped for a mini-solarstorm that would bring us aurora, both in pictures and in propagation modes, but it looks like we will need to wait for a change in the weather. As STEREO-A creeps ever closer to us in its slow approach to Earth, it can give us great insights into what things will be like tomorrow. But nothing is ever a guarantee. It's a good lesson to remember.
"Cheers, Tamitha."
https://www.youtube.com/watch?v=MUSd2293p_I
Her report from a few days earlier:
https://www.youtube.com/watch?v=E-Qo4aqldDc
Gert Carlsson, AA7G sends along this information on the IY4M interactive beacon robot:
http://www.cqdx.ru/ham/ham_radio/iy4m-marconi-cw-beacon-robot/
Mark Lunday, WD4ELG of Greensboro, North Carolina reported on June 9:
"I am here in my shack in central NC, truly amazed. 41 years in the hobby; that does not happen too often these days. Surprises, yes.
Pure amazement, infrequent.
"But here I sit. It's 2300 LOCAL time (0300 UTC), I called CQ on 17 meters FT8 with 25 watts and a 160 meter inverted L with a remote coupler at the base. I got a reply from JH7VHZ. This is a non-directional wire, no gain, 90 feet vertical and 42 feet angled down 45 degrees, with 20 radials, in a forest of pine trees, fed with 300 feet of coax from my shack. At 11 PM local! And HE called ME. Sure it was FT8, but that's not the point.
"Last time I worked JA from east coast on the higher bands (it's not that common for me here, with my antenna setup) was two years ago on 15 meters in the ARRL DX SSB contest. Sure I can occasionally hear them, very weak, but it's not easy to get through. (Of course it's much easier on 40 meters than 20/17/15)
"The last time I worked JA at that late an hour when it was NOT on 40 meters, was September 2012, on SSB on 20. Before that, it was 21 years ago when I was closer to the ocean in Florida, so I had better propagation.
"And before that time in 1997, it was 1979, I was in W6 land, the bands were ON FIRE, I had a dipole at 20 feet on a hill about a mile from the Pacific ocean, and 15 meters was open well past sunset to JA and UA0 out west. I used to run CW pileups in DX contests at high speed until 10 PM local on 10 meters, then switch to 15 meters until midnight, then work them on 20 until I fell asleep at my desk around 0200 (oh how I wish I had that energy of a 14 year old today.)
"But I digress.
"We complain (well, I COMPLAIN) about the poor band conditions, but maybe it's also factor of not having more activity during sunspot cycle lows. FT8 is a game changer, and it seems like activity has really increased, especially DX.
"On 17 meters FT8, I am also copying E5 and UA9. VERY strong. On FT8 on 20 meters, I am copying VK/ZL, EU, 9K. All very workable, very strong. 20 seems to be what it was at sunspot peak, always open, frequently capable of worldwide DX especially at night. Now THAT is how I remember 1979. 20 was ALWAYS open. Like it is tonight."
Bob Lombardi, W4ATM of Melbourne, Florida on June 11 wrote:
"I had been starting to refer to the sporadic-E propagation we had from about June 1st and well into last week as 'The Great Sporadic-E Opening of June 2018.' Morning checks on DXMaps would show the density of transatlantic propagation to/from Europe at densities I've never seen. For the first time in my life, I saw DX contacts reported from Japan into the SE US one evening, including one into my grid square. (I was having dinner and missed the brief chance).
'I've been operating on 6m since about '03, and the June contest has always been the most productive weekend of the year for me. Last year, after hearing about this new thing called FT8 while following DX spots, I started experimenting with that mode and have played with it a bit. Not expert level, but I know my way around it.
"Last Monday, my country total in Europe went from 1 to 4.
"I suppose the attack of Murphy's Law for the contest was predictable, but Saturday was the worst day I've seen since late May. Sunday was better, but new grids were hard to find, and my ultimate hope of completing my 6-meter WAS never had a chance. Not one KH6 or KL7 to the mainland was seen all weekend. The vast majority of the grid locators I heard were among the first I ever worked: FN, FM, EM and the eastern half of EN. I did manage to work a few Canadian grid squares I've never gotten before, into Saskatchewan and Alberta, and a couple in the lower 48.
"Of course, there's a reason it's called 'sporadic,' and what little we had this weekend was better than nothing, but what a contest it would have been if the propagation hadn't peaked a week before the contest.
"I'm left to wonder if this really was a June sporadic-E season for the record books or if it's some combination of more people online and reporting, more activity on 6, or the influence of FT8. The few times I looked at the modes being reported, it seemed 80 of the reports were FT8."
Jeff, N8II reported:
"I worked CT1ESV, Portugal today June 14 at 2230Z, S8 on 10M phone.
DXMAPS.com showed NA stations working S01WS Western Sahara on 6M FT8 and there were NA to EU QSOs too."
F.K. Janda, OK1HH reports.
"Geomagnetic activity forecast for the period June 15 to July 10, 2018
"Geomagnetic field will be:
Quiet on June 20-24, July 2-3
Quiet to unsettled on June 16-19
Quiet to active on June 15, 25, July 1
Unsettled to active on June (26, 30)
Active to disturbed on June (27,) 28, (29)
"Solar wind will intensify on June (15,) 16-17, (18-19, 22-24, 26,) 27-29, (30,) July 1, (9-10)
"Remark:
- Parenthesis means lower probability of activity enhancement.
- Due to planned trips, this forecast will not be compiled from June 21st (or 28th) to July 5th."
If you would like to make a comment or have a tip for our readers, email the author at k7ra@arrl.net.
For more information concerning radio propagation, see the ARRL Technical Information Service at http://arrl.org/propagation-of-rf-signals.
For an explanation of 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.
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Sunspot numbers for June 7-13, 2018 were 0, 0, 0, 0, 0, 12, and 16, with a mean of 4. 10.7 cm flux was 69.3, 68.2, 66.8, 70.2, 69.9, 70.3, and 70.8, with a mean of 69.4. Estimated planetary A indices were 6, 4, 4, 4, 4, 4, and 5, with a mean of 4.4. Estimated mid-latitude A indices were 6, 5, 5, 4, 4, 5, and 7, with a mean of 5.1.
