The K7RA Solar Update

SEATTLE, WA, Jan 7, 2005--Happy New Year! Not much to say about solar numbers or propagation this week compared to last, except that Thursday, January 6, had wonderfully quiet geomagnetic numbers. Both the mid-latitude and planetary A index numbers were four, and for most of the three-hour periods the each K index was zero or one.

Of course, sunspot numbers will continue to decline for the next couple of years, but at least we can count on better conditions for the near term as the hours of daylight lengthen.

Because it's now 2005, we can tally the numbers for last year and compare them with the past to try to get a feeling for cycle 23's decline. These quarterly and yearly averages are derived from the daily sunspot and solar flux data reported at the end of each bulletin.

From the third quarter of 2003 through the fourth quarter of 2004, average daily sunspot numbers were 110.2, 99.2, 72.9, 71.3, 69.3 and 61. The average daily solar flux for the same period was 120.8, 137.4, 111.1, 99.5, 111 and 104.8. Quarterly sunspot numbers and flux values have declined steadily, although there are some variations, such as solar flux in the fourth quarter of 2004 being higher than it was in the second quarter.

Average daily sunspot numbers for the years 2000 through 2004 were 173, 170.3, 176.6, 109.2 and 68.6. Average daily solar flux for the same five-year period was 179.6, 181.6, 179.5, 129.2 and 106.6. We can see the steady decline with each calendar year, and this trend should continue through the end of 2006.

Now for the short term conditions: A week ago it looked like the solar flux would stay above 100 over the following 10-12 days. Now the last of sunspot 715 is disappearing around the edge of the sun, and it looks like solar flux should stay around 85 with sunspot numbers below 40 over the next week.

Saturday, January 8, could experience some unsettled to active geomagnetic conditions, and January 13 could see unsettled conditions as well. Quiet days are expected January 10-11.

Alan Beck, VY2WU, from Prince Edward Island, Canada, wrote in response to last week's mention of 60 meters. He said in northern Canada 60 meters is used for "bush radio," and he told about Inuit hunters in Nunavut using 5.2 MHz SSB at 10 W to call home from the ice.

Barry Roseman, W0LHK, of Stilwell, Kansas, wrote to say he was on 60 meters the first day it opened for US hams. Roseman says he knows of only four operators, including himself, who have worked all states on 60 meters. The others are K7NN, N1UU and K4AVC. His best DX was G0HNW. W0LHK has used various dipole antennas and a quarter-wave vertical, and says he often works mobile stations on the band.

For more information concerning propagation and an explanation of the numbers used in this bulletin see the ARRL Technical Information Service Propagation page.

Sunspot numbers for December 30 through January 5 were 34, 60, 51, 52, 43, 30 and 15 with a mean of 40.7. The 10.7 cm flux was 100, 98.5, 98.9, 100, 94.2, 88 and 88, with a mean of 95.4. Estimated planetary A indices were 15, 8, 15, 33, 22, 23 and 21 with a mean of 19.6. Estimated mid-latitude A indices were 12, 5, 10, 20, 14, 16 and 11, with a mean of 12.6.

Amateur solar observer Tad Cook, K7RA, Seattle, Washington, provides this weekly report on solar conditions and propagation. This report also is available via W1AW every Frida,y and an abbreviated version also appears in The ARRL Letter. Readers may contact the author via e-mail.

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