Solar activity increased last week. Compared to the previous seven days, average daily sunspot number increased from 1.6 to 12.6, while average daily solar flux rose from 68.9 to 71. After six days with sunspots making a re-appearance (October 12-17), there were no sunspots on Thursday, October 18.
Sunspot area was listed at zero on October 15-17, which means that the area was less than 10 millionths of a solar hemisphere. See ftp://ftp.swpc.noaa.gov/pub/indices/DSD.txt for daily sunspot area.
Geomagnetic indicators were quieter. Average daily planetary A index dropped from 14.1 to 7.4, and average mid-latitude A index went from 10.3. to 7.3.
Predicted solar flux is 70 on October 19-22, 68 on October 23-26, 69 on October 27 to November 4, 70 on November 5-6, rising to 72 on November 7-17, 70 on November 18-20, 69 on November 21 to December 1, and 70 on December 2.
Predicted planetary A index is 18, 10 and 8 on October 19-21, 5 on October 22-23, 10 on October 24, 8 on October 25-26, 5 on October 27 through November 2, then 22 and 20 on November 3-4, 15 on November 5-6, then 8, 5, 12, 8 and 10 on November 7-11, 5 on November 12-13, then 12, 18, 10, 5, 10 and 8 on November 14-19, 5 on November 20-21, 10 on November 22, 5 on November 23-29, then 22, 18 and 10 on November 30 through December 2.
Geomagnetic activity forecast for the period October 19 to November 14, 2018 from F.K. Janda, OK1HH.
Geomagnetic field will be:
Quiet on October and on November 2, 13-14
Quiet to unsettled on October 21, 24, 31, and on November 1, 8, 10, 12
Quiet to active on October 20, 27, 29-30, and on November 11
Unsettled to active on October 22-23, 25-26, and on November 5-7, 9
Active to disturbed on October 19, (28,) and on November 3-4
Solar wind will intensify on October 19-20, 30-31 and on November 3-6, (7-9,) 10-13.
Remarks:
- Parenthesis means lower probability of activity enhancement.
- Again, there are changes in the configuration of active areas, so the predictability of the prognoses decreases, and their compilation is difficult.
From Dr. Tamitha Skov: Once again, we find ourselves in a waiting game with the Sun. Not only do we have a repeat offender-- a coronal hole that sent us fast solar wind last month is about to send some again-- but we also have several active regions firing small solar flares and mini-solar storms. This burst of eruptive activity is a bit surprising because the Sun has been in near hibernation for a while now. I captured my excitement in the above picture (unfortunately, no way to display the image in the propagation bulletin but watch the video). I taped labels "1" and "2" on my screen to show where two near-simultaneous eruptions occurred on opposite sides of the Sun on October 12. (Although I accidentally blocked the timestamp, the time of the first was 1355 UTC and the second was 1415 UTC.) I wanted to share this with you so when you watch the STEREO segment in the video, you will know when and exactly where on the Sun to focus your eyes!
So, the obvious question is, ‘Will any of these eruptions hit Earth?’ Right now, likely not. But it does feel good to watch active regions for solar storm launches again, even if this is only a momentary burst of activity. Nonetheless, if none of the recently launched mini-solar storms hit Earth, we still have fast wind from coronal holes to keep us busy, which arguably could last us through the entire solar minimum!
Speaking of, in the forecast this week I talk about the fast solar wind coming from the northern coronal hole and how long we must wait before it arrives. I also look back at how much it affected us last month and why its effects should be reduced this time around. Overall, this is good news in the wake of Hurricane Michael. A report I saw in News4JAX today said the North Florida section of the American Radio Relay League is still actively looking for emergency radio responders to fill the ongoing communication gaps across the Florida Panhandle. Knowing that the impact of Michael is still being felt, I am grateful that the bulk of Space Weather right now comes from predictable sources like coronal holes. There is no doubt I get excited seeing a flurry of eruptions occurring on the Sun, especially when they might hit Earth. But I must admit this week, I would prefer to wait for nothing.
Dr Skov’s latest video is here: https://youtu.be/9uhUlyHhXzI
NASA explains the difference between CMEs and solar flares. Thanks to ARRL Contest Update and NW7US for the link: https://www.youtube.com/watch?v=TWjtYSRlOUI
NN4X sent this link concerning “NASA Scientists See Gravity Waves from Storms in Earth’s Atmosphere:” https://twitter.com/i/moments/1053091974746583040
Jon, N0JK, sent this note: "A surprise 6 meter sporadic-E opening the evening of October 13. A minor G-1 class geomagnetic storm was in progress. Kp = 4.
“Stations in the Gulf Coast and South Texas had Es to the Midwest and Rocky Mountain states. K0GU (DN70) said he heard the K4TQR/b (EM63) for 2 hours. I heard the K4TQR/b on my mobile while driving on I-70 near Junction City, Kansas. Es is rare in October, the only month with less sporadic-E is March."
Martin, WB5AGZ, sent this: "I don't know when it started, but I was checking a few high HF frequencies starting at about 0010 UTC on October 14 and found lots of activity on several CB channels, so I tuned up to 10 meters and heard several signals such as a local rag chew in the Albany, Georgia area on about 28.39 MHZ. At least one of the stations in the conversation was running on generator power due to damage to the power grid from Hurricane Florence.
“I then tuned up to 50.125 MHz, which is usually full of signals if there is a real band opening, but I heard no signals at all, nor were there any 10-meter repeaters audible from North Central Oklahoma. It appeared that the E skip was anemic and the MUF was probably between 28.5 and 29 MHz.
“The Winter (E[s]) season doesn't normally start until November, but Sporadic E isn't much for reading the rules and it can pop up about any time. Continuously active low VHF and high HF frequencies are a lot harder to come by than they used to be, so it pays to store a few frequencies in your receiver memories if you have them to spare.
“I have the following pre-sets stored, with all frequencies in MHz: In AM, all WWV frequencies plus all the CHU frequencies, the highest CHU frequency being 14.67 MHZ USB with carrier. Then there is CB Channel 6 in which folks run enormous levels of power, possibly trying to crowd-source an artificial ionosphere! Think HAARP only a bit out of tune.
“If you don't hear any skip signals on 27.025, you can almost safely assume there is not much happening between 25 and 50 or 60 MHz.
“If you have FM reception capabilities, definitely pre-set 29.6 and 29.62 or everything between 29.6 and 29.68 MHz as 10-meter repeaters make excellent propagation indicators when they are in use.
“I just step through them quickly to see if anything non-local is there."
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 October 11 through 17, 2018 were 0, 11, 22, 22, 11, 11, and 11, with a mean of 12.6. 10.7 cm flux was 70.9, 71.6, 72.4, 71.5, 70, 69.7, and 70, with a mean of 71. Estimated planetary A indices were 9, 5, 14, 6, 10, 5, and 3, with a mean of 7.4. Estimated mid-latitude A indices were 7, 14, 12, 4, 7, 4, and 3, with a mean of 7.3.
