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The K7RA Solar Update (09/02/2022)

The past week saw many interesting events. The DRAO observatory at Penticton, British Columbia (the source of 10.7 cm solar flux measurements) was overwhelmed by solar flares, and at 2000 UTC on August 28 reported a solar flux value of 251.9, and the next day at 1700 UTC, a value of 357.1.

The 2000 UTC local noon numbers are the official solar flux number for each day, so for the August 28 value I chose to report the 2300 UTC number of 133.5 instead.

I checked with astronomer Andrew Gray at Penticton, and he reported, "The high values are indeed because of solar activity, both yesterday and today flares occurred right during our flux measurements."

Solar activity increased this reporting week (August 25-31) with average daily sunspot numbers rising from 58.7 to 74.9 and solar flux from 104.5 to 123.8.

Without that correction for August 28, average daily solar flux would have been 140.8 instead of 123.8.

I have seen these errors in the past, but they are rare. When they occur, there is only 1/3 chance they will happen during the daily 2000 UTC reading, which sends them into the official daily solar flux data.

Note that NOAA did not correct the high false value:

Average daily A index was a little lower, the planetary values shifting from 12.6 to 10.1 and middle latitude from 11 to 9.4.

Three new sunspot groups appeared on August 25 at the beginning of the reporting week, but none until September 1, with two new sunspot groups. The daily sunspot number rose from 42 on Wednesday to 67 on Thursday. Total sunspot area peaked on August 27.

Predicted solar flux is more optimistic in the Thursday night version, as opposed to the Wednesday forecast reported in the ARRL Letter.

Instead of 110 on September 2, the latest forecast is 116, 118 and 118 on September 2-4, 115 on September 5, 110 on September 6-8, then 118, 124, 130 and 128 on September 9-12, then 120, 117, 105 and 102 on September 13-16, then 98 on September 17-18, then 104, 102 and 108 on September 19-21, 118 on September 22-23, 124 and 125 on September 24-25, 120 on September 26-28, 115 on September 29 to October 1, then 112 on October 2, 108 on October 3-4, then 115, 120, 124 and 130 on October 5-8.

Flux values may briefly dip below 100 in mid-October.

Predicted planetary A index is 10, 15, 30, 25 and 15 on September 2-6, 10 on September 7-8, 12 and 8 on September 9-10, 5 on September 11-12, then 12, 15 and 10 on September 13-15, 8 on September 16-17, 5 on September 18-23, then 14, 10 and 8 on September 24-26, 5 on September 27-29, then 30, 38, 20, 15, 18, 10, 12 and 8 on September 30 through October 7, and 5 on October 8-9.

At 0209 UTC on September 2 the Australian Space Weather Forecasting Centre issued a geomagnetic disturbance warning: "Disturbed conditions caused by a high speed wind stream in a geoeffective direction are expected September 3-5."

Frantislav K. Janda, OK1HH shares his weekly commentary:

"The recent rise in solar activity, especially during August 27-30, was triggered by two sunspot groups, AR3088, which on 29 August fell behind the western limb of the solar disk, and AR3089, which on 30 August passed through the central meridian, so entered the region of the so-called present active longitudes.

"Both sunspot groups are in the southern hemisphere of the Sun, while in both were daily registered flares of moderate magnitude. CMEs have been registered in four cases. Given the proximity of the coronal hole, we would expect a significant increase in geomagnetic activity, but only at first approach.

"However, there was only a slight increase in geomagnetic activity, confirming the current solar wind path models. We expect it to intensify and then increase in geomagnetic activity since about September 4 onwards. A further gradual increase in total solar activity can be expected a few days later."

I (K7RA) noticed some curious 12 meter propagation, testing the band using FT8 on This way I can see instantly where my signal is heard, and get accurate, objective signal reports.

On August 31 at 2038-2116 UTC my calls were heard nowhere in North America outside my local area, which were stations 4-54 miles away. But all stations hearing me were in a straight line running through Mexico and Central America, then down to Brazil.

XE1GLL, XE1EE, and XE1AQY, down to V31MA, LU6FL and PU3MSR. No 12 meter resonant antenna, just a 32 foot end-fed indoor wire fed with a 4:1 UnUn transformer and automatic antenna tuner.

Other curious 12 meter behavior was on Saturday, August 27 at 2252 UTC when the only stations hearing me (FT8 again) were ZL2OK at 7,120 miles with a strong signal report of +4 dB and WH6FXV at 2,649 miles.

Ten minutes later at 2302 UTC JA1QGI was the only station reporting, from 4,746 miles away. Four minutes later JN4MIV reported. At 2312 UTC ZL2OK was back, this time reporting -4 dB, 8 dB lower than the earlier report.

At 2315 UTC I worked JH6RKI and copied several more Japanese stations.

Newsweek Magazine has been reporting interesting solar news recently:

And Forbes.

Is "The Independent" one of the UK Fleet Street tabloids? Perhaps a RSGB member could inform us.

Another wonderful report from Dr. Tamitha Skov, WX6SWW, ham radio's own Space Weather Woman:

In the following links, many are presented for your amusement only. I do not believe that a huge solar flare will ever engulf the Earth.

A canyon of fire:

EarthSky reports (page down):

A report four weeks old, but still relevant:

Growing sunspot a threat:

Our angry Sun:

This one is a bit over the top:

From a few days ago:

Radio blackouts:

Flares and blackouts:

Existential threat:

Flare facing Earth:

Sunspot somehow destroys Earth:

The 61st annual All Asian DX Phone contest is this weekend.

Information can be found here:

Send your tips, reports, observations, questions, and comments to

For more information concerning shortwave radio propagation, see and the ARRL Technical Information Service at . For an explanation of numbers used in this bulletin, see .

An archive of past propagation bulletins is at . More good information and tutorials on propagation are at .

Instructions for starting or ending email distribution of ARRL bulletins are at .

Sunspot numbers for August 25 through 31, 2022 were 94, 88, 84, 79, 87, 50, and 42, with a mean of 74.9. 10.7 cm flux was 117.8, 118.6, 127.5, 133.5, 130.6, 125.6, and 113.3, with a mean of 123.8. Estimated planetary A indices were 5, 5, 14, 7, 14, 13, and 13, with a mean of 10.1. Middle latitude A index was 5, 5, 11, 7, 13, 13, and 12, with a mean of 9.4.


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