This week saw sunspot numbers and solar flux decline. Average daily sunspot numbers declined from 199.3 to 138.7, while solar flux dropped from 162.9 to 149.7.

Sharp eyed readers may notice that we reported average daily sunspot numbers last week at 202.4, not 199.3, but we just noticed a discrepancy between what last week’s bulletin reported for March 4-5 and what we see now from NOAA. I don’t know if NOAA revised the sunspot numbers for those days, or we just made a mistake, but instead of sunspot numbers of 171 and 202 on March 4-5, they were actually 160 and 191. This brings the average sunspot number for that week down from 202.4 to 199.3

Also in question is the mid-latitude A index on March 12, reported as 3. I had to make a calculated estimate at the time because something interfered with collection of data from the Fredericksburg, Virginia station from around 1500 UTC on March 12 until 2100 UTC on March 13. The first four K index readings on March 12 came in at 2, 0, 1 and 2 and the last three readings on March 13 at 2, 0 and 3. The A index for the day is calculated from the eight K index measurements.

The most recent prediction has solar flux at 145 on March 14-15, 140 on March 16-20, 135 on March 21-22, then 145, 150 and 145 on March 23-25, 140 on March 26-27, 135 on March 28-29, then 130, 125 and 120 on March 30 through April 1, 115 on April 2-4, and 110 on April 5-7. Flux values would then rise to a high of 140 on April 20, which is not very high, but that is a long way out, more than seven weeks away.

Predicted planetary A index is 5 on March 14-16, 8 on March 17-18, 5 on March 19-29, 8 on March 30 through April 1, 5 on April 2-5, and then 12, 10 and 8 on April 6-8, then back to 5 again until April 26.

OK1HH sends us his weekly geomagnetic forecast from the Czech Republic, on behalf of the Czech Propagation Interest Group. He and OK1MGW began doing these in 1978. The geomagnetic field will be quiet to unsettled March 14-15, mostly quiet March 16-17, quiet to active March 18-19, active to disturbed March 20, quiet to active March 21, quiet to unsettled March 22, quiet March 23-24, quiet to active March 25, quiet March 26, quiet to active March 27, mostly quiet March 28-31, quiet April 1-2, quiet to unsettled April 3, active to disturbed April 4, and quiet to active April 5.

Space.com has an interesting article about a great geomagnetic disturbance and aurora 25 years ago in March, 1989. Read it at http://www.space.com/24983-auroras-1989-great-solar-storm.html and click on the photos. I noticed in the third photo there seems to be an HF dipole in the picture, and part of an HF Yagi element in the fifth image. These are credited to Ken Spencer of Sea Cliff, New York, and sure enough, 25 years later there is still a Kenneth Spencer in Sea Cliff, N2AQQ.

Fred Glen, K9SO, of Palatine, Illinois wrote about what happened on March 8, from 0130-0230 UTC: “It's a very rare event for me to work a new country these days after I passed the 250 country mark but something very unusual happened tonight on 10 and 12 meters. In a one-hour period I nabbed 4 all-time new countries on CW: China, Hong Kong, Brunei, and Taiwan. Maybe not all that rare, but they are when you don't have them in the log. That part of the world has always been a black hole for me usually losing to west coast stations. I also worked into South Korea and Singapore. Signals were very weak, but workable on my dipole up 35 feet. What a night! Can we expect more?”

John Boudreau, VE8EV of Inuvik, about 124 miles north of the Arctic Circle in Canada’s Northwest Territories writes about some amazing conditions way up north.

“The bulletin last week didn't even begin to hint at the outstanding high band propagation we've been having from the Western Arctic. After the X-class flare on Feb 27 the HF bands were completely dead here from top to bottom for several days, but began to pick up during the ARRL DX Contest. For a week afterwards the propagation has been the best I have ever seen from our far Northern location.

“The ‘three anchors’ of low auroral activity, low D-region absorption, and very high solar flux rarely appear at the same time on the propagation slot machine of auroral zone HF. Ten meters has been open around the clock for days now. Strong signals from North and South America during the daytime, Asia in the evenings, and then to Europe and Africa from local midnight right through until morning. I've surprised many European stations that were not expecting to hear signals from North America at those hours. Best DX was ZS8C, 11000 miles away on Marion Island at 7:30 AM my local time. Conditions like this sure make up for the many days we spend vainly trying to get out from under the aurora here.”

Thanks, John! What a great report.

On March 9, Jon Jones, N0JK, sent this: “I usually don't operate much on HF, preferring 6 meters. But I went out this evening mobile after seeing lots of DX spotted. Mobile set up is FT-987, RadioShack stock CB mag-mount whip and an MFJ tuner to get the SWR down enough to get some RF into it.

“10 meters was very good this evening. I worked BG3UPA in Taiyuan, Shanxi, China on 10 CW at 2359 UTC March-9-2014. I recorded him on my cell phone - very loud at times. Took a few calls but did it.

“It is the first time I have contacted an amateur radio station in China. He is over 11,000 km from Kansas. Also heard but didn't work Charlie, VR2XMT. I worked Charlie on 6 meters from HC8N back in 2001. Other DX heard on 10 were JT1, HS0, and V85.

“I think the recent high solar flux and low K index have been favorable for these paths on 10 meters.”

Jeff Hartley, N8II, of Shepherdstown, West Virginia wrote: “It has been quite a couple of weeks since the major flare on Feb 27-28 just prior to the ARRL DX contest.

“Ten meters has been the best band into SE Asia (due north from here) from around 2300Z until about 0100Z with the best example being G6PZ/MM in the Gulf of Thailand a solid S5 on 10 meter CW at 0048Z on the 9th. Openings to Mongolia on 10 are quite rare here, but the band was open 3-4 days in a row with JT1AA/3 logged at a solid S9 at 0110Z on the 8th. JT1BV was heard the day before on both phone and CW about S6-7 at best, but the pile ups were too big to get through. On the 9th, JT1AA/3 was again loud and on the 10th he was about S3.

“These are some of the best conditions to East Asia I can ever remember on 10, but I am fairly certain it was as good or better near the peak of the last cycle when I was focused on 6 and 12 meters. The solar flux has been running from the 140s to 160s with seemingly little difference in conditions between the low and high and K indices have been mostly 0-1. I can usually at least hear almost every station spotted on 10, but not hear nearly as well on 12 or 15 meters where some rare DX has also been worked.

“Some of the highlights are hearing Christmas Island VK9X/K7CO in both the morning and evening on 15 and 10 with our mornings being better on 15 and logging them on both 10 meter phone and CW (0108Z) as well as QRP running 5W on 15 phone at 1634 on the March 7. I have heard/worked day after day around 1300-1400Z on 12 and 10 meters. VU2XO makes daily appearances on 10 phone about S9 on better days and almost daily also hearing Datta, VU2DSI, on 10 meters. Kazakhstan has been very active with the KEDR suffix stations commemorating Yuri Gagarin's eightieth birthday. There are some big signals out of there for sure, with almost all of the UP prefix/KEDR numbers being logged on mostly 15, 12, and 10 meters. ZS8C on Marion Island was logged on 10 meter phone at 1453Z on the March 5. Countless times he has been spotted on 15 phone with no signal here. On 10 in the evening zone 18 Russians have been logged (rare from here) as well as many in zone 19, many Chinese, VR2UW, 9L1A, BV1EK (also on 12 meters), BV8SG, 9V1, V85NL, and several DS/HL stations. In the mornings on 10, several UN/UPs, zone 17/18, from Russia, 9M2IDJ were logged. Also on 15 phone at 1300Z, VK6NTE was worked peaking at about 350 degrees rather than the true heading of about 315. The seasonal shift to more daylight over the North Pole has really been felt in late February and early March.”

Ron Freeman, W0YF, of Omaha, Nebraska wrote on March 13: “The past few days have been really wild on 10 meter JT-65HF. Sunday through Wednesday were wide open. It was neat to follow the sun as I worked Russia, Turkey, Finland, and then Greenland. On to North and South America and then to VK and ZL and JA lands with even a couple of Chinese stations. Finally and all in one operating session, I was back to RW0CD via long path. It's now Thursday and things have cooled off a bit, but I'm still seeing Russia, Mexico and Belgium.

“The rig here is a FT-950 at 25 watts and a modest Hustler 4BTV (4 band, trapped vertical) disguised as a flag pole, due to HOA restrictions. Operating system is Debian Linux.”

That’s cool. For more information on the JT-65HF mode, go to the ARRL website at www.arrl.org/ and in the website search box on the upper right, search for “jt65”.

Note the spring equinox will be here in just a few days! The first day of spring is Thursday, March 20, and the equinox occurs at 1657 UTC. Both the southern and northern hemispheres will be bathed in equal measures of solar radiation. The equinox is a great time for HF propagation.


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 March 6 through 12 were 174, 161, 138, 123, 122, 108, and 145, with a mean of 138.7. 10.7 cm flux was 148.8, 148.2, 141.6, 145.9, 151.5, 164.6, and 147.6, with a mean of 149.7. Estimated planetary A indices were 6, 4, 4, 3, 6, 4, and 6, with a mean of 4.7. Estimated mid-latitude A indices were 5, 3, 5, 2, 4, 4, and 3, with a mean of 3.7.