The K7RA Solar Update

No sunspots appeared this week. Solar flux was about the same as last week. The 45-day outlook for solar flux and planetary A index from NOAA and the Air Force on February 10 was predicting a flat solar flux of 70; the following day, this was revised to show 72 for February 12-18, then 70 after that. On February 12, this changed to show 72 solar flux for February 13 through the rest of the 45 days.

Sunspot numbers for February 7-13 were 0, 0, 0, 0, 0, 0 and 0 with a mean of 0. The 10.7 cm flux was 70.8, 70.9, 72.2, 72.6, 72.1, 72.1 and 70.5 with a mean of 71.6. Estimated planetary A indices were 5, 4, 2, 18, 17, 11 and 12 with a mean of 9.9. Estimated mid-latitude A indices were 6, 3, 2, 13, 16, 6 and 10 with a mean of 8.

For February 10-13, we saw increased geomagnetic activity due to another solar wind stream. The planetary A index -- calculated from a number of mostly higher latitude magnetometers -- was 18, 17, 11 and 12 for those four days. Alaska's college A index, measured near Fairbanks, was 42, 31, 22 and 26, illustrating the increased geomagnetic activity toward the poles in response to space weather. Here at mid-latitudes, where many of us live, the A index (measured in Virginia) was 13, 16, 6 and 10. That magnetometer is near 38.3 degrees north latitude, which is a little south, and of course way east of the Boulder site (at 40.1 degrees north latitude), where we get the K and A index reported on WWV.

Jon Jones, N0JK of Wichita, Kansas, reports some February E-skip openings on 6 meters. He writes, "E-skip tends to become scarce in February, and March has the lowest occurrence of E-skip of any month." On February 2 he worked XE2YWB in Central Mexico (DL82) at 2237 UTC on 50.125 MHz with S7 signals. The next day he worked K4EU in Virginia via E-skip on 10 meters. K4EU reported working stations throughout the Midwest that day.

Ed Swynar, VE3CUI, of Newcastle, Ontario, took issue with a statement in last week's bulletin about the absence of sunspots being great for 160 meters. "Such mythology could not be further from the truth this year. The band has been most unremarkable this season, to say the least, and it continues to languish away in the doldrums. I thought that perhaps it was something at fault at my end: however, many subscribers to W4ZV's Topband Reflector seem to be of the same opinion." Readers have sent similar reports about both 160 and 75 meters over the past year. It seems that low geomagnetic and sunspot activity should be good for the lower frequencies, but perhaps it is not always the case.

Over the past week many, many e-mails arrived from readers with a link to an article in a daily business publication claiming that we are on the verge of another Maunder Minimum, a decades-long period of little or no sunspot activity that occurred roughly between the years 1640-1710. The article appeared with no byline, quoting Dr Kenneth Tapping of the Herzberg Institute of Astrophysics in Penticton, British Columbia; this is the observatory that supplies our daily solar flux values. But I thought the quotes sounded a little strange and not like Ken. Some readers also felt this way. As one wrote, "The article didn't quite ring true," and "I have a fairly broad scientific reading list."

I sent Ken an e-mail. He responded that this has been a difficult week for him. A few weeks ago he received a phone call from a woman who engaged him in "a long discussion involving possibilities ranging from likely to not likely." He wrote that the article promotes something that is untrue, and "in no way do I support the conclusions she assigned to me."

I think we can relax about any possible upcoming 70-year period of a quiet Sun. We cannot say that it could not happen, but in fact there is nothing unusual about the current Solar Cycle minimum, and really no known method of predicting such a period.

This weekend is the ARRL International DX CW Contest. The geomagnetic field is expected to be quiet.

Last weekend I watched an interesting DVD from the local library, a 1994 documentary titled Picture of Light. This has some nice time-lapse long-exposure moving images of aurora, taken in Churchill, Manitoba, on Hudson Bay above 58 degrees north latitude.

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 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.

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