QST de W1AW
Propagation Forecast Bulletin 14 ARLP014
From Tad Cook, K7VVV
Seattle, WA April 5, 2002
To all radio amateurs
SB PROP ARL ARLP014
ARLP014 Propagation de K7VVV
Average daily solar flux rose last week by 27 points, and average sunspot numbers by over 9 points. We've had active geomagnetic conditions this week caused by a stream of high speed solar wind, yielding aurora displays at high latitudes. Saturday through Wednesday were very active, with a number of three-hour periods when the planetary K index was 4.
Solar flux for the short term is expected to peak around 215 for Friday and Saturday, then drift below 200 after Tuesday. Geomagnetic conditions could become slightly active or unsettled on Saturday.
Currently there is a large complex of sunspots crossing the visible solar disk. A helioseismic image also shows a pair of large sunspots on the sun's far side.
Kenzo Nose, JA3EGE wrote in about some great recent 6-meter openings he observed in Japan. On March 17 from 2035 to 2300z he worked stations in the South Pacific, and long path into Europe and the Caribbean. He said it was the most unusual propagation he has observed in 30 years. He worked 9H1, EH3, IS0, IT9, EH6, FJ5, FM5, FG5, PJ2, YV5 and P49.
You can reach Kenzo via email at email@example.com. You can reach the author of this bulletin at firstname.lastname@example.org.
The beginning of April marked the end of the first quarter of 2002 so it is time to look at some of the numbers.
Average daily sunspot numbers for the last five quarters, from January 1, 2001 to March 31, 2002 were 147.3, 164.8, 170.4, 198.1 and 178.3. Average daily solar flux for the same five periods was 164.4, 166.7, 175.5, 219.1 and 203.9. Both solar flux and sunspot numbers were higher this past quarter than the first three quarters of 2001, but lower than the last quarter of last year, which had a lot of activity.
Average sunspot numbers for the past five months, November through March, were 178.6, 217.5, 189, 194.5 and 153.1. Average daily solar flux for the same five months was 215.8, 236.5, 227.3, 205, and 179.5.
We can definitely see the peak that occurred around December, and that January of this year had more activity than November of last year. But March solar flux and sunspots were definitely down.
Sunspot numbers for March 28 through April 3 were 144, 189, 171, 133, 189, 262 and 162 with a mean of 178.6. 10.7 cm flux was 176.2, 181.3, 188.7, 204.4, 207, 206 and 209.4, with a mean of 196.1, and estimated planetary A indices were 6, 7, 17, 14, 16, 15 and 13 with a mean of 12.6.