On Wednesday, December 19 Spaceweather.com displayed this headline: “Solar minimum conditions are in effect”, followed by "The Sun has been without sunspots for 209 days in 2018--that is, 59% of the time. To find a similar stretch of blank suns, you have to go back to 2009 when the Sun was experiencing the deepest solar minimum in a century."
Looking at my own records, I show the average daily sunspot number for all of 2009 was 5.05, and average daily solar flux was 70.6.
Examining data from the past two months (October 19 through December 19) the same values were 3.6 and 69.4, so we are clearly down in the same sort of minima.
Of course, there are many ways to slice and dice the numbers, so rather than 3.6 and 69.4 from the past two months, looking at all the numbers for 2018 so far, we see averages of 6.6 and 69.9.
Average daily sunspot numbers for the past week were 3.4 (there were only two days with any visible sunspots) which was down from 9.7 in the previous week.
Average daily solar flux declined only slightly from 70.7 to 70.4.
Average planetary A index decreased from 8 to 4.1, while average mid-latitude A index went from 6.4 to 3.
Predicted solar flux for the next 45 days is 70 on December 21-23, 72 on December 24, 70 on December 25-27, 72 on December 28 through January 4, 70 on January 5-16, 72 on January 17-31, and 70 on February 1-3.
Predicted planetary A index is 8, 5 and 5 on December 21-23, then 8, 5 and 5 again on December 24-26, then 8 on December 27-28, then 12, 10 and 8 on December 29-31, 5 on January 1-2, then 10, 12, 10, 10 and 8 on January 3-7, 5 on January 8-12, 8 on January 13, 5 on January 14-23, then 8, 12, 10 and 8 on January 24-27, 5 on January 28-29, then 10, 12, 10, 10 and 8 on January 30 through February 3.
Geomagnetic activity forecast for the period December 21 to January 16, 2019 from F.K. Janda, OK1HH.
Geomagnetic field will be:
Quiet on December 23, 25-27, January 10-12
Quiet to unsettled on December 21-22, 24, January 9, 13
Quiet to active on December 28, January 1-2
Unsettled to active on December 29, (31), January (3-5,) 6-8, 14
Active to disturbed on December (30,) January (15-16)
Solar wind will intensify on November 30 and on December (24-27,) 28-31, January 1, (3-4,) 5-7, (8, 14,) 15-16
Remark:
- Parenthesis means lower probability of activity enhancement.
Here is an exchange between Gedas Vysniauskas, W8BYA, and Jon Jones, N0JK, about their activity during the Geminid meteor shower, which peaked on December 14: “Hi Jon, I’m so excited, I just had to share this with you. After over 6-7 years of trying, KE7NR/P in DM54ah and myself completed a contact on 2-meter meteor scatter using MSK144 several days before the Geminid peak date. I had a good feeling when, right off the bat, I received this +20 dB decode from him:
150700 20 20.2 1527 & W8BYA KE7NR DM54
Anyway, this was very late in the morning and it represents my best 2-meter non-EME DX at 1425 miles, and non-EME grid #373.”
“Gedas, I ended up with 9 Geminids meteor-scatter contacts on 6 meters. All while using MSK144. My best DX was probably a contact with W3CP in grid EM74. I also enjoyed some short-distance meteor-scatter contacts as with KV5W in EM22 and K0TPP in EM48. I Saw decodes on K0WDO in EM17, N0LWF in EN10, and several on KA9CFD in EN40, which are close in and would imply high MUF. I was on in the early morning of December 14 running 100 W to a 3-element Yagi antenna.”
Here is the latest video from Dr. Skov, the Space Weather Woman: https://youtu.be/wt-T-mbt5Ag
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 December 13 through 19, 2018 were 0, 12, 12, 0, 0, 0, and 0, with a mean of 3.4. 10.7 cm flux was 70.2, 70.8, 71.2, 69.8, 70.1, 70.4, and 70.2, with a mean of 70.4. Estimated planetary A indices were 3, 3, 2, 2, 6, 7, and 6, with a mean of 4.1. Estimated mid-latitude A indices were 2, 3, 1, 1, 5, 5, and 4, with a mean of 3.
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