The K7RA Solar Update

Photo:NORTHERN LIGHTS AT 34,000 FEET: A minor stream of solar wind hit Earth’s magnetic field on Dec. 18th. The impact did not cause a geomagnetic storm, but it did light up Arctic skies. Hongming Zheng saw the show while flying 34,000ft above Anchorage, Alaska:

Still no sunspots, and it’s been the same for 37 consecutive days.

Geomagnetic conditions remained quiet, until “a minor stream of solar wind” (according to Spaceweather.com) hit us on December 18. This drove the planetary A index to 13 from the low single digit values earlier in the week.

Average planetary A index for December 12-18 rose to 4.6, from 3.7 over the previous 7 days, while mid-latitude A index increased from 1.9 to 4.

Predicted solar flux over the next 45 days is 70, and we’ve seen this same daily 45-day flux forecast since December 2. December 1 was the last time there was any value in the forecast other than 70 when they predicted 69 for December 23 through January 4. The forecast is updated daily at ftp://ftp.swpc.noaa.gov/pub/forecasts/45DF/ .

Predicted planetary A index from the same forecast is 8 on December 20-21, 5 on December 22 through January 4, 8 on January 5, 5 on January 6-8, 8 on January 9-10, 5 on January 11-13, 12 on January 14, 10 on January 15-17, 5 on January 18-31, 8 on February 1, and 5 on January 2.

Geomagnetic activity forecast for the period December 20, 2019 until January 15, 2020 from OK1HH.

Geomagnetic field will be
Quiet on: December 28-31, January 1-4, 8
Quiet to unsettled on: December 21-27, January 7, 9-13
Quiet to active on: (December 20, January 5-6)
Unsettled to active on: (January 14-15)
There are no disturbed conditions in this forecast.

Solar wind will intensify on: January (14,) 15 (-16)

– Parenthesis means lower probability of activity enhancement.
– Everything suggests that we are very close to the minimum of the 11-year cycle at present stage of development.

Naturally, because of weak solar activity, the ARRL 10 Meter Contest last weekend was rather slow. Jon Jones, N0JK from Kansas wrote: “With a solar flux of 70 and a low K index, not much F-layer propagation was expected in the 2019 ARRL 10-Meter contest.

“But Sunday afternoon I found a strong 10 Meter opening to Argentina and Chile from Kansas. I set up ‘fixed mobile’ with 5 watts and a 1/4 wave whip on the car at around 1800z December 15. I didn’t expect much, but heard several very loud stations from South America on CW. I put CE2ML and LW8DQ in the log. Signals were up to 599. I wonder if this was a ‘Es – TEP’ opening?

“When I got home, I checked DXMaps. It showed what appeared to be an Es cloud over Louisiana. This may have supported 10 Meter propagation on to CE and LU. Es can raise the MUF when the signal hits the F-Layer and are often strong. It was a nice treat for an otherwise slow contest.”

Here at K7RA using a very limited low-elevation random-wire antenna, I checked 10 meters in the last hour of the contest on Sunday looking to hand out a few contacts. I heard no local stations here in the Seattle area on SSB but did manage to work some CW operators.

N8II reported the following to the 3830 contesting forum (excerpts): “The F2 opening to the south was much better Saturday. The Geminids meteor shower did coincide with the contest this year which saved the day especially for the big guns.

“Friday, Saturday morning and evening, and Sunday morning I was able to work meteor scatter on CW in all directions and there was some activity from most of the states/provinces within the approximate 1500-mile meteor-scatter range. For example, I worked all W1 except RI and all of eastern Canada except NL, PE and NU. I worked 4 NB stations, about 1-2 via brief sporadic E.

“There was a short sporadic E opening late Sunday around 2127-2205Z to TX, AR, IA but again activity was low. Sunday was a real grinder with most stations already worked. The meteor scatter died out around 1600Z Sunday. F2 was limited to Brazil and Chile here from 2016-2057Z. It was difficult to work PY even when above S5 here; I guess many locations in PY have high noise levels.”

Here is the latest video forecast from Dr. Skov, WX6SWW: https://bit.ly/2MeZrBh

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 http://www.arrl.org/propagation and 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.

Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins.

Sunspot numbers for December 12 through 18, 2019 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 70.5, 68.9, 70.3, 71, 70, 70.5, and 70.2, with a mean of 70.2. Estimated planetary A indices were 4, 4, 3, 5, 1, 2, and 13, with a mean of 4.6. Middle latitude A index was 3, 3, 2, 5, 1, 2, and 12, with a mean of 4.

Source:ARRL