Propagation de K7RA 15 October

Propagation de K7RA

15 October

At 0326 UTC on October 12 the Australian Space Forecast Centre issued a Geomagnetic Disturbance Warning:
"The high speed streams associated with a recurrent positive polarity Northern hemisphere coronal hole are expected to persist for a few days. If the Bz component of the IMF turned strongly southward for prolonged periods, earth could experience Minor Storm conditions on 13 October."

"Increased geomagnetic activity expected due to a coronal hole high speed wind stream for 13 October 2017."

Earlier Spaceweather.com reported, "A hole in the Sun's atmosphere is spewing solar wind toward Earth, and this is sparking bright auroras around the poles on October 11. At the time of this alert, a G1-class geomagnetic storm is underway. NOAA forecasters estimate a 70 percent chance of continued storms at high latitudes on October12 and 13 as Earth moves deeper into the solar wind stream. Visit http://www.spaceweather.com for pictures and updated forecasts."

There were no sunspots visible on October 8 through 12, and the last new sunspot to appear was September 25, which was still visible on October 7, but not since then.

Average daily sunspot numbers for the past week (October 5-11) dropped from 32.6 the previous seven days to 8.4. Average daily solar flux declined from 87.9 to 76.8. Geomagnetic activity also dropped but is now increasing. Average daily planetary A index went from 16.3 to 8.9, and average mid-latitude A index went from 12.7 to 8.

Predicted solar flux is 70 on October 13-17, then 72 on October 18-19, 80 on October 20-31, 76 on November 1-5, 74 on November 6-14, 76 on November 15, and 80 on November 16-26.

Predicted planetary A index is 35, 25, 20, 10, and 8 on October 13-17, 12 on October 18-19, 5 on October 20-23, then 35 and 45 on October 24-25, 15 on October 26-27, then 10 and 8 on October 28-29, 5 on October 30-31, then 8 and 10 on November 1-2, 5 on November 3-5, then 8, 25, 30, 36, 28, 16 and 8 on November 6-12, 5 on November 13-19, then 35 and 45 on November 20-21, 15 on November 22-23, then 10, 8 and 5 on November 24-26.

Geomagnetic activity forecast for the period October 13 to November 8, 2017 from F.K. Janda, OK1HH.
"Geomagnetic field will be:
Quiet on October and November-irregularly Mostly quiet on October and November-irregularly Quiet to unsettled October (18-22, 24,) 28-29, (30-31,) November (1-2, 4-6) Quiet to active on October 13-16, (17, 23,) 26-27, November 3, 7 Active to disturbed on October 25, November 8
"Amplifications of the solar wind, mostly from coronal holes, are expected on October 12-17, (18, 22, 24,) 25-26, November 7-12

http://www.southgatearc.org/propagation/k7ra/index.htm#.WeSjj4_Wzct