ARLP043 Propagation de K7VVV:
October 18, 2002

Propagation Forecast Bulletin 43 ARLP043
From Tad Cook, K7VVV
Seattle, WA October 18, 2002
To all radio amateurs

ARLP043 Propagation de K7VVV

Sunspots and solar flux were higher over the past week. Average daily sunspot values increased by more than 46 points over the previous week, and average solar flux was up by nearly 20. Geomagnetic conditions were unsettled to active. The most active days were Thursday and Monday (October 10th and 14th) when planetary A indices were 23 and 26. The really quiet day was Friday, with a planetary A index of 8 and mid-latitude A index of only 5.

Solar flux should drop over the next couple of weeks to around 140 by October 27-29, then turn up again at the end of the month. Over the next few days, Friday though Tuesday, approximate solar flux values are predicted around 180 to 185. The earth is currently within a high-speed solar wind, and we could see a jump in geomagnetic activity if the interplanetary magnetic field tilts south. Planetary A indices are predicted around 12-15 over the next few days, an unsettled outlook.

Last week we mentioned the book, "Storms from the Sun." Michael Carlowicz, a science writer at the Woods Hole Oceanographic Institution is one of the authors and wrote to say he is available to speak at larger amateur radio club gatherings and hamfests. He is in Massachusetts, and can most easily reach southern New Hampshire and Vermont, most areas of Massachusetts, Connecticut, Rhode Island and New Jersey, New York City and the Hudson Valley, District of Columbia, Eastern Pennsylvania and Northern Virginia.

He will also be in the San Francisco Bay area December 7-12, and his co-author, who lives in Texas, may be available to speak in Texas and New Mexico. You can contact Michael via email at, Also check out the excellent website devoted to the book at, . Don't miss the Space Weather links page.

Michael sent along this abstract from a talk he gives:

"We live within the atmosphere of a variable star, and that atmosphere is home to some of the most bizarre and unpredictable cosmic weather. Space weather is a range of disturbances that are born on the Sun (flares, sunspots, coronal mass ejections), rush across interplanetary space, and disturb Earth's environment and the various technologies we have come to depend upon."

He goes on to say,

"If you like your electronic toys and tools--or if you work for or invest in the companies that make them--you ought to learn something more about your nearest star...the only one that will affect you in your lifetime."

Sunspot numbers for October 10 through 16 were 244, 178, 171, 167, 175, 165, and 182, with a mean of 183.1. 10.7 cm flux was 171.9, 179.4, 180.4, 179.2, 181.2, 176.8, and 182.5, with a mean of 178.8. Estimated planetary A indices were 23, 8, 11, 10, 26, 15, and 14, with a mean of 15.3.