ARLP051 Propagation de K7RA
More sunspots emerged this week, with every December day so far
showing spots. In addition to the sunspot numbers listed through
Wednesday at the end of this bulletin, Thursday, December 6 had a
sunspot number of 29. The daily sunspot number has not been this
high since mid-July. Two spots are now visible, 977 and 978, and
the total coverage of the solar surface by sunspots on Thursday is
four times Wednesday's coverage. Average daily sunspot number for
this report is over twice last week's, rising from 5.4 to 11.1.
Sunspots will probably continue until at least December 13.
Geomagnetic numbers have been extremely low, with average daily
planetary A index dropping from 8.7 to 2, and average mid-latitude A
index declining from 6.3 to 1.1 for the week. Check the quarterly
geomagnetic indices since October 1 at,
http://www.swpc.noaa.gov/ftpdir/indices/quar_DGD.txt, and note the
incredibly stable numbers, especially at high and mid-latitudes,
around December 2-6. You don't see strings of zeroes such as this
during the higher portions of the solar cycle, and it seems
perfectly timed with last week's ARRL 160 meter contest. Heightened
or unsettled to active geomagnetic conditions are not expected until
December 17.
Geophysical Institute Prague predicts quiet conditions December 7-9,
quiet to unsettled December 10, unsettled December 11-12, and quiet
to unsettled December 13.
This year we've been tracking a 3-month moving average of daily
sunspot numbers to help spot trends that may indicate the bottom of
the solar cycle. Here are the 3-month averages since December 2005.
Dec 05 40.6
Jan 06 32.4
Feb 06 18.1
Mar 06 27.7
Apr 06 38.5
May 06 39.7
Jun 06 28.9
Jul 06 23.3
Aug 06 23.5
Sep 06 21.2
Oct 06 24.1
Nov 06 23.1
Dec 06 27.3
Jan 07 22.7
Feb 07 18.5
Mar 07 11.2
Apr 07 12.2
May 07 15.8
Jun 07 18.7
Jul 07 15.4
Aug 07 10.2
Sep 07 5.4
Oct 07 3.0
The average for September, October and November, centered on
October, at 3 is the lowest yet for this side of Cycle 23. This
number was derived by adding all daily sunspot numbers for those
three months, then dividing the sum (270) by the number of days,
which is 91. The result is approximately 2.967, very close to 3.
Monthly sunspot number averages for this year, January through
November, are 28.2, 17.3, 9.8, 6.9, 19.8, 20.7, 15.6, 9.9, 4.8, 1.3
and 2.9. October's average of 1.3 is lower than September and
October of 1996, during the minimum between Cycles 22 and 23. The
monthly averages for August through November, 1996 were 20.7, 2.9,
2.3 and 25.6.
A new table of predicted sunspot and solar flux values for Cycle 24
is in this week's Preliminary Report and Forecast of Geophysical
Data at, http://www.swpc.noaa.gov/weekly/ on pages 10-11, December 4
issue. For the past few years the prediction table showed no data
beyond this month. The table now runs an additional eight years,
through December 2015.
Note the two sets of predicted smoothed sunspot data, reflecting the
split consensus among members of the Cycle 24 prediction panel at
this year's Space Weather Workshop in Boulder, Colorado. The late
decline in Cycle 23 led the group away from an earlier consensus for
a strong Cycle 24, and now the panel is split. One faction predicts
moderately strong sunspot activity for Cycle 24, the other,
moderately weak.
You can see from the table of values that
the strong camp shows a peak centered near August-November 2011,
while
the weak cycle faction predicts their peak to occur in May-October 2012.
The OT prediction? (Jan 2007)
Cycle will build and peak over the period October 2010 and Feb 2013.
22 years from 1988/ 89 will be the maxima around Dec 2010 to October 2011.
Serious EU dx openings Dec 2010 to Feb 2011 from VK3. Between 0700 and 1200 UTC.
Better from further North and West.
I reckon!