QST de W1AW
Propagation Forecast Bulletin 1 ARLP001
>From Tad Cook, K7RA
Seattle, WA January 7, 2005
To all radio amateurs
SB PROP ARL ARLP001
ARLP001 Propagation de K7RA
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 mid-latitude and the planetary A index were 4, and for most of the three-hour periods the K index was 0 or 1.
Of course, sunspot numbers will continue their 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 the year is now 2005, we can tally up numbers for the previous year and compare them with the past to try to get a feeling for Cycle 23's decline. These quarterly and yearly averages are made 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.
Both the 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 years was 179.6, 181.6, 179.5, 129.2 and 106.6. We can see the steady decline with each calendar year, and this should continue through the end of next year, 2006.
Now for conditions over the short term, a week ago it looked like solar flux should 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 see 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 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 a story about Inuit hunters in Nunavut using 5.2 MHz SSB at 10 watts 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 U.S. hams. Barry says only four stations have worked all states on 60 meters: K7NN, N1UU, K4AVC, and himself, W0LHK. His best DX was G0HNW in Yorkshire. Barry has used various dipole antennas and a quarter-wave vertical, and says he often works mobile stations.
If you would like to comment or have a tip, email the author at, firstname.lastname@example.org.
For more information concerning propagation and an explanation of the numbers used in this bulletin see the ARRL Technical Information Service propagation page at, http://www.arrl.org/tis/info/propagation.html.
Sunspot numbers for December 30 through January 5 were 34, 60, 51, 52, 43, 30 and 15 with a mean of 40.7. 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.