venerdì 15 novembre 2019

The K7RA Solar Update

Even with little to no solar activity, it is amazing how many long-distance HF contacts are possible, even without using weak signal modes such as FT8.

Recent DXpeditions, such as the ones on Pitcairn Island and Marquesas, had little trouble piling up the contacts, even on ten meters. It helps that we are in the fall season.

No sunspots over the past week, and average daily solar flux was about the same as last week’s report, 70.3 compared to 70.4. Geomagnetic indices were still quiet, with average daily planetary A index at 4 (last week was 4.1) and middle latitude A index at 3 (compared to 2.7).

Predicted solar flux is 71 on November 15 to December 3, 70 on December 4-18, and 71 on December 19-29.

Predicted planetary A index is 5, 12 and 8 on November 15-17, 5 on November 18-19, then 18, 25, 18, 12 and 10 on November 20-24, 8 on November 25-26, 5 on November 27 through December 16, then 15, 25, 18, 12 and 10 on December 17-21, 8 on December 22-23, and 5 on December 24-29.

This forecast is the same as the one appearing on Thursday in the ARRL Letter. Check daily updates at ftp://ftp.swpc.noaa.gov/pub/forecasts/45DF/. These are updated daily after 2100 UTC, most recently between 2110-2151 UTC.

Geomagnetic activity forecast for the period November 15-December 10, 2019 from OK1HH.

Geomagnetic field will be
Quiet on: November 18-19, 29-30, December 1
Quiet to unsettled on: November 15, 27-28, December 4-10
Quiet to active on: November 16 (-17, 25-26), December 2-3
Unsettled to active on: November 20, 24
Active to disturbed: November 21-23

Solar wind will intensify on: November 21-26, (27-29)

Parenthesis means lower probability of activity enhancement.

Bil Paul, KD6JUI, is still operating regularly from his kayak in Northern California. QST published an article about his boat and antenna in the November 2016 issue. "I was again operating from a kayak (November 9, Saturday), this time from Lake Berryessa in northern California. The first contact I had (17-meter CW at noon Pacific time) was with "Moz" VK3CWB in Australia. I was, as before, running 10 W into a 34-foot end-fed half-wave wire vertical set up in a fallen-over tree at the edge of the lake. Although at first, he had trouble copying my call sign, he did give me a 539 report.

“What amazed me was that directly behind me was a hill that I thought would cut my signal in his direction. Perhaps my signal was bouncing off the hills on the other side of the lake.

“One of my reasons for writing in is to show that QRP signals even in this time of low solar activity can get through overseas, especially if one is operating from a watery location.

“I go out in the kayak around once a week and operate. The antenna is loadable on 17, 20 and 30 meters. There was plenty of activity on all those bands yesterday, but I only had contacts on 17 and 30. My buddy caught his first trout on his end of things. A good day all around.

“I get a very good QSL-card return from foreign stations when I send them my kayak QSL card.”

KA3JAW reported an 11-meter sporadic-E opening on the evening of November 13. Local sunset was 4:44 PM and the opening began 2 hours and 31 minutes later and ended 4 hours and 16 minutes after sunset. He is in Easton, Pennsylvania and heard transmissions from Alabama, Georgia, Kentucky, North Carolina, South Carolina, and Virginia.

ARRL Phone Sweepstakes is this weekend. See http://www.arrl.org/sweepstakes

Here is an interesting page from NASA showing how solar rotation varies according to latitude: https://www.nasa.gov/mission_pages/sunearth/science/solar-rotation.html. Thanks to N2IC and N0AX via ARRL Contest Update.

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.

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



Sunspot numbers for November 7 through 13, 2019 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 69.8, 70.2, 69.6, 70.8, 69.5, 70.8, and 71.1, with a mean of 70.3. Estimated planetary A indices were 5, 3, 4, 3, 7, 4, and 2, with a mean of 4. Middle latitude A index was 3, 2, 3, 2, 7, 3, and 1, with a mean of 3.


http://www.arrl.org/news/the-k7ra-solar-update-603