“ASWFC GEOMAGNETIC DISTURBANCE WARNING ISSUED AT 2306 UTC 16 NOVEMBER 2023 BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.
“Two recent CMEs associated with small solar filament eruptions are
expected to increase geomagnetic activity from mid 19-Nov to 20-Nov.
“INCREASED GEOMAGNETIC ACTIVITY EXPECTED DUE TO CORONAL MASS EJECTION FROM 19-20 NOVEMBER 2023.”
Solar activity was lower this week, November 9-15, with average
daily sunspot numbers dropping from 89.7 to 80.1, and average daily
solar flux from 151.7 to 133.8.
If these numbers seem a little low lately, we should check the
bulletin from the same week last year.
In the November 18, 2022 bulletin average daily sunspot number
changed from 79.8 to 72.3, so a year later we are definitely still
trending higher.
Geomagnetic indicators were also lower, planetary A index changing
from 22.3 to 10.4, and middle latitude A index from 14.6 to 8.6.
A single new sunspot group appeared on November 10, another on
November 12, one more on November 13 and another on November 14.
Predicted solar flux is 118 and 120 on November 17-18, 122 on
November 19-22, then 126, 135 and 135 on November 23-25, then 140,
148, and 152 November 26-28, 155 on November 29 through December 1,
then 152, 150, 148 and 145 on December 2-5, then 140 on December
6-8, then 145, 135, 130 and 125 on December 9-12, 120 on December
13-15, then 125, 128, 130 and 132 on December 16-19, 135 on December
20-22, 140 and 148 on December 23-24, and 152 on December 25-26.
Predicted planetary A index is 8, 5, 15, 26 and 10 on November
17-21, then 5, 10, 18, 20 and 12 on November 22-26, 8 on November
27-28, 5 on November 29 through December 3, then 10, 16, 12 and 10
on December 4-7, 5 on December 8-9, 8 on December 10-13, then 5 on
December 14-18, then 15, 12, 18, 20, and 12 no December 19-23, and 8
on December 24-25.
Weekly Commentary on the Sun, the Magnetosphere, and the Earth’s
Ionosphere November 17-23, 2023 from OK1HH:
“During the first half of November, solar activity continuously
decreased, which was not what we would have liked for shortwave
propagation.
“Even worse, there were relatively few geomagnetically quiet days –
only November 2, 3, 11 and 14.
“There were more days with higher geomagnetic activity: 4-8, 13 and
15 November. In addition, high levels of free electrons were present
in the ionosphere during relatively long periods (up to 4 November
and 7-12 November), which contributed to an increase in the
attenuation of passing electromagnetic waves.
“Shortwave propagation conditions in the second half of the month
should definitely be better as solar activity is expected to
increase. In addition, with the exception of the last days of
November (when we expect a disturbance), we expect the geomagnetic
field to be mostly quiet to only moderately active.
“If we try to account for the 27-day recurrence, geomagnetically
active days with fluctuations in propagation should occur after
November 21 again, but this is really only a guess given the current
nature of the trend.”
Check this site for an update on current conditions on various
bands:
https://dr2w.de/dx-propagation/
From Dick Bingham, W7WKR, an article about Heliophysics and amateur
radio:
https://bit.ly/46jYf5O
An article from NOAA about Sunspots/Solar Cycle:
https://bit.ly/47iUpv2
Send your tips, reports, observations, questions, and comments to
k7ra@arrl.net. When reporting observations, don’t forget to tell us
which mode you were operating.
An archive of past propagation bulletins is at
. More good
information and tutorials on propagation are at .
Also, check this article from September, 2002 QST:
https://bit.ly/3Rc8Njt
Instructions for starting or ending email distribution of ARRL
bulletins are at .
Sunspot numbers for November 9 through 15, 2023 were 93, 93, 85, 78,
85, 86, and 41, with a mean of 80.1. 10.7 cm flux was 138.7, 143.9,
141.5, 137.2, 132.7, 123.8, and 118.9, with a mean of 133.8.
Estimated planetary A indices were 12, 10, 5, 12, 16, 6, and 12,
with a mean of 10.4. Middle latitude A index was 8, 7, 4, 10, 15, 5,
and 11, with a mean of 8.6.