The K7RA Solar Update
Recent sunspot activity is increasing, and the numbers bear this out. The average daily sunspot number for 2009 was 5 and the average for 2008 was 4.7. There's not much difference in those numbers, but those are for calendar years; the trend toward the end of 2009 was increasing sunspot activity. The average daily sunspot numbers for 1999-2009 were 136.3, 173, 170.3, 176.6, 109.2, 68.6, 48.9, 26.1, 12.8, 4.7 and 5. On Wednesday of this week, the sunspot number was 0, but it rose to 15 on Thursday with the appearance of new sunspot group 1040. Coming this weekend, sunspot groups 1036 and 1038 are due to return, although we don't know yet if they are still powerful enough to be classed as sunspots. Sunspot numbers for December 31-January 6 were 16, 16, 22, 20, 15, 13 and 0, with a mean of 14.6. The 10.7 cm flux was 79.9, 75.2, 78, 76.4, 73, 76.8 and 77.3, with a mean of 76.7. The estimated planetary A indices were 1, 1, 0, 3, 2, 1 and 1, with a mean of 1.3. The estimated mid-latitude A indices were 0, 2, 1, 3, 1, 1 and 0, with a mean of 1.1.
A few years ago, we began recording a moving average of daily sunspot numbers based on three calendar months in order to help us spot a sunspot cycle bottom, thinking that this would perhaps give us a more immediate indication than smoothed sunspot numbers, which use a whole year of data. Because we now have all of the sunspot numbers for December, we can calculate the three month average centered on November 2009 -- 10.16 -- which is the highest it has been since August 2007 when it was 10.17. We will know the average centered on December at the end of January.
Over the past couple of years, it looked like the moving average bottomed out several times. In late 2007, it appeared we hit bottom when the three-month average centered on October dropped to 3. Then the average rose and was in the range of 8.23 to 8.89, centered on December 2007-April 2008. The average then declined again, hitting 1.1 in August 2008. In September-November, it moved to 2.5, 4.52 and 4.39, then declined to a new minimum of 1.5 in March, 2009. From there it rose, stalled and rose dramatically when from April through November 2009 it was 2.01, 4.23, 5.2, 4, 4, 4.64, 7.1 and 10.163. The average daily sunspot number for just the month of December was 15.7, which is a good trend -- 5.54 points higher than the 3-month average.
The latest prediction is for geomagnetic conditions to remain quiet, with the anticipated planetary A index at 5. But looking at recent predictions from USAF/NOAA, that value is probably a maximum, since they have predicted that value almost every day for months, and actual numbers were better (lower). Check the table and note that the planetary A index hasn't gone as high as 5; as of Friday morning, the last time it rose to 4 was December 14. The same prediction shows solar flux at 79 for today (January 8), 80 on January 9-10, 82 on January 11, 84 on January 12 and 86 for January 13-15.
Regarding recent conditions, last week, Jeff Hartley, N8II, of Shepherdstown, West Virginia, said in a New Year's Eve e-mail that conditions seemed poorer on the higher bands (17 meters and up) than the solar activity would suggest. But then Jeff saw better conditions on lower frequencies: "Last night, the 30th was exceptional on 30, 80 and 160. Several loud longpath JAs were worked on 30 meters; I tried 20 meters longpath to no avail around 2320UTC. Then signals from northern EU and other EU were booming in on 160 from 0020-0130 UTC and I caught TF3SG on SSB. All of the EUs heard on 80 at the same time were loud, and 4S7NE was about S6-7 on 80 CW around 0120 UTC near his sunrise, attracting a crowd."
Last week, we had an interesting email exchange with Jerry Spring, VE6CNU, of Calgary, Alberta. Carl Luetzelschwab, K9LA, commented on them when I passed Jerry's e-mail on to him. Jerry thinks that HF conditions are poorer than expected, given the solar activity. He feels that conditions have not improved, and wonders if there needs to be a certain threshold of activity, enough to "kick-start" the F layers of the ionosphere.
Carl's comment was that we really haven't seen much sunspot activity, enough to raise the MUF (Maximum Usable Frequency). Carl analyzed ionosonde data from Wallops Island in Virginia from last August and attached a graph representing the rise and fall of MUF from day to day. He wrote, "It shows the day-to-day variation of the F2 region MUF over the Wallops Island ionosonde, assuming it's the midpoint of a 3000 km hop. Note that the MUF varies from a low of 11.6 MHz to a high of 21.5 MHz -- and to reiterate, this is with zero sunspots and no change in solar flux. Thus, there are other factors that ultimately determine the ionization -- and these are geomagnetic field activity and events in the lower atmosphere coupling up to the ionosphere. Surprisingly, the day-to-day variation of the F2 region is more due to these two factors than a small change in sunspots or solar flux. In fact, these two factors generally mask any small increase in sunspots and solar flux." Carl emphasized that only when the sunspot activity rises significantly will we see any long term improvements. When we notice an improvement in propagation, it may be due to other factors, including seasonal changes.
Don't miss Carl's personal Web site, a great resource devoted to propagation. He writes the excellent monthly propagation column for WorldRadio Online, with a new issue on the 20th of each month. Note on that page that there is a link on the left to back issues, beginning with February 2009.
Tom Russell, N4KG, of Harvest, Alabama, lives for 160 and 80 meters. He has an impressive array of antenna arrays at his place in the woods west of Huntsville, including large ground plane antennas for 80 and 160, an inverted-L for 160 and dipoles on 80. In fact, I was just admiring his antennas, not from his photos, but publicly available aerial images. I went to a search engine and clicked on "Maps," then entered his address and ZIP code from his license record. He is actually west of the location that you land on, at the end of a road. Click on "Aerial," then "Bird's Eye" -- note you can click on vantage points from four directions and can also zoom in. Look for multiple telltale Yagis in the woods. Tom tells us that November and December had some fantastic 160 and 80 meter conditions and he sent a long log listing of contacts in Russia and Northern Europe from December 11-13, most from December 12 and most on 160 meters. He notes more shortpath UA9s in two months than in 30 years operating in Northern Alabama. He says that "these Russian openings are not daily events by any means, but there have been (and continue to be) several very good nights (and mornings). My friend N4NO -- he holds a PhD in electromagnetic field theory and communications and is a very active DXer -- suggested that these openings are the result of historically low geomagnetic activity, a 'seminal event.'"
Among his contacts over those days on 160 (mostly CW) were 4O3A, EI2CN, ES2DJ, LA5HE, LY2J, LZ1ANA (S9++), RA0ALM (Zone 18, just north of JT), RA1AOB, RA3DOX, RA4LW, RU3DX, RU4SU, RX4HZ, RX9FM (Zone 17), SM6CPY, TF3SG, TF4M, UA3BS, UA3TCJ, UA4CC, UA4HBW, UA9MA, UR0MC, UW7CN, UX1UA, UY0ZG, YL2SM and ZC4VJ. On 80 meters he worked RA4CC, RK3ER, SM4OTI (S9+), TF3SG (S9 SSB), UA3TCJ, UA4HBW, UA4LY, UA9FMZ, UA9YAB, UU9DX and UX4UU. At the end of it all, his amplifier died on December 13 and then he worked RA0ALM, RA1AOB and UA3TCJ barefoot.
Tom reported that on January 2 "RZ0AF has been camping out on 160 and 80 meters (3521), morning and night, around 1200 to 1300 UTC and Friday evening from 2300-0400 UTC, well past his sunrise which is around 0200 UTC. He is located in Krasnoyarsk, about 300 miles north of the northwest border with Mongolia, in Zone 18. Is there a Big 160 meter station in UA0Y (Zone 23 -- my last needed Zone on 160 meters)? UA9MA has also been active on 160 and 80 meters from Omsk in the southeastern corner of Zone 17, peaking 569 on 3524 at 0342 UTC last night (January 2 in GMT). UA9KAA was running NA on 1823 (up 1) from 0500-0600 UTC, peaking 569 at times. He is in Northern Siberia in Zone 17. RX4HZ was 599+ on 40 meters with a little help from his 4L Quad at 30 meters high at 0600 UTC."
The STEREO Mission has been a tremendous asset. This year, it is expected to move into a position that allows us to see magnetic activity on the whole Sun. This weekend, on January 9 at 0836 UTC, the two satellites will be in position to see 87 percent of the Sun, with the invisible spot on the far side exactly 13 percent. It will achieve 88 percent coverage (with 12 percent invisible) at 0611 UTC on February 25, 2010.
Amateur solar observer Tad Cook, K7RA, of Seattle, Washington, provides this weekly report on solar conditions and propagation. This report also is available via W1AW every Friday, and an abbreviated version appears each Thursday in The ARRL Letter. Check here for a detailed explanation of the numbers used in this bulletin. An archive of past propagation bulletins can be found here. You can find monthly propagation charts between four USA regions and 12 overseas locations here. Readers may contact the author via e-mail.