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The K7RA Solar Update

08/07/2020

Tad Cook, K7RA, Seattle, reports: Sunspot Cycle 25 is under way. We saw one new spot on July 28 and two new ones on August 2 and 3. The daily sunspot numbers were 22 and 23 on the dates of their appearance, and the total sunspot area grew on Wednesday to 160 millionths of the visible solar disc. The total sunspot area was smaller the next day, August 6, but the daily sunspot number increased from 13 to 14.

Sunspot area has not been as large since May 2019, when it ranged from 140 to 410 millionths of the solar disc over a 2-week period.

Average daily sunspot number for July 30 – August 5 was 19.6, up from 14.1 over the previous 7 days. Average daily solar flux rose from 71.1 to 72.8 over the same period.

The A index remained about the same, with planetary A index barely increasing from 6.7 to 7 and mid-latitude A index declining slightly from 8.7 to 7.4.

Predicted solar flux is 73 on August 7 – 9; 71 on August 10 – 14; 69 on August 15 – 17; 71 on August 18 – 25; 73 on August 26 – 30; 71 on August 31 – September 7; 69 on September 8 – 13, and 71 on September 14 – 20.

The planetary A index forecast is 5 on August 7; 8 on August 8; 5 on August 9 – 23; 8 on August 24 – 25; 5 on August 26 – 28; 12, 8, and 8 on August 29 – 31; 5 on September 1 – 19, and 8 on September 20.

Geomagnetic activity forecast for the period August 7 – September 2, 2020 from F.K. Janda, OK1HH. “Geomagnetic field will be:

  • Quiet on August 7 (– 8,) 12, 15 – 16, September 2

  • Quiet to unsettled on August 9, 11, 13 – 14, 17 – 19, 22, (23 – 27,) 28 – 29, September 1

  • Quiet to active on (August 10, 20 – 21)

  • Unsettled to active on August (30 – 31)

  • Active to disturbed not expected

  • Solar wind will intensify on: August (10 – 11, 22 23,) 24 – 25, September 1 – 2

Notes: Parenthesis means lower probability of activity enhancement. The predictability of changes remains lower because there are few indications, moreover, in new active areas.

Geomagnetic conditions have been very quiet and stable for a long time, and this week is the first time in recent memory that OK1HH has predicted any unsettled-to-active conditions.

Frank Donovan, W3LPL, noted on August 5: “Today marks the longest stretch of consecutive days with sunspots since September 2017, when there were 56 consecutive days.

“The next Solar Cycle 25 milestone will be an energetic sunspot region that increases the adjusted SFI to 80 or higher. Fingers and toes crossed...”

WJ5O has an interesting history of 10-meter sporadic-E and info on beacons.

Frequent contributor Ken Brown, N4SO, wrote us from the Gulf Coast in Grand Bay, Alabama. He noted an announcement about the Reverse Beacon Network map display.

“On a ‘Dead Band,’ I get the following from a series of CQs:

W8WTS N4SO 21035.1 CW CQ 4 dB 28 wpm 1722z 06 Aug 70 seconds ago

KO7SS N4SO 21033.1 CW CQ 23 dB 28 wpm 1721z 06 Aug 2 minutes ago

W3UA N4SO 21033.1 CW CQ 13 dB 28 wpm 1721z 06 Aug 2 minutes ago

W3RGA N4SO 21033 CW CQ 23 dB 28 wpm 1721z 06 Aug 2 minutes ago

W3RGA N4SO 21035 CW CQ 20 dB 28 wpm 1721z 06 Aug 2 minutes ago

K1TTT N4SO 21035 CW CQ 6 dB 28 wpm 1720z 06 Aug 3 minutes ago”

“On CW, 21-MHz frequencies will often appear dead from 21.000 to 21.060 MHz. For a quick propagation check, I will often use W1AW on their CW broadcasts.

“On 21 MHz (21.0675 MHz), the 3 PM (5 August) code practice, for example, had no signals at all, and the Reverse Beacon Network did not show a spot for 5 August, and confirms no signals. On several odd days in the past, there are signals just above the noise level to about S1 or S2.

“28 MHz has a broadcast on 28.0675 MHz. In addition to propagation checks, I use the signals from W1AW for a frequency calibration check.

“On the Reverse Beacon Network, I will often do a W1AW spot check, which shows dates and times past history, for W1AW and the frequencies when they were spotted.”

David Moore noticed this item in Science Daily about our quiet sun being much more active than it appears.

Occasionally, we ponder past geomagnetic storms so huge that if they occurred today with our dependence on technology, it seems as if they could end life as we know it. In the past, they have even appeared during periods of otherwise low sunspot activity, such as this one.

Astrophysicist Nigel Weiss, who studied the interaction between the rotation and magnetic field of the sun behind sunspots and solar flares, has died at age 83.

Sunspot numbers for July 30 – August 5, 2020 were 22, 23, 22, 22, 23, 12, and 13, with a mean of 19.6. The 10.7-centimeter flux was 73.3, 72.3, 72, 72.7, 72.7, 73, and 73.4, with a mean of 72.8. Estimated planetary A indices were 4, 4, 3, 9, 16, 8, and 5, with a mean of 7. Middle latitude A index was 5, 5, 3, 9, 15, 9, and 6, with a mean of 7.4.

For more information concerning radio propagation, visit the ARRL Technical Information Service, read “What the Numbers Mean…,” and check out K9LA’s Propagation Page.

A propagation bulletin archive is available. Monthly charts are no longer be updated on this page. For customizable propagation charts, visit the VOACAP Online for Ham Radio website.

Instructions for starting or ending email distribution of ARRL bulletins are on the ARRL website.

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