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A glancing CME impact is expected late on 13 July and another CME
impact is expected early on 15 July.  These impacts present the
possibility of geomagnetic storm activity over 13 to 15 July.  We
saw a welcome rise in solar activity this reporting week, July 6 to
12.  Referencing the previous seven days, average daily sunspot
numbers rose from 126.1 to 181.9, while average daily solar flux
increased from 164.5 to 179.4.  On July 13 the solar flux was 202.9,
well above the average for the previous seven days.  Geomagnetic
indicators did not change much, average planetary A index going from
7.3 to 8.6 and average daily middle latitude A index from 8 to 8.1.
The most active day was July 7 when University of Alaskas college A
index was 40.  The middle latitude A index on that day was only 11.
The college A index is from a magnetometer in Fairbanks.  What is
the outlook for the next month?  Predicted solar flux looks great
over the next few days, at 200, 202, 198, 200, and 204 on July 14 to
18, 202 on July 19 to 21, 160 on July 22 and 23, 155 on July 24 and
25, 160 on July 26 and 27, 165 on July 28 and 29, 170 on July 30 and
31, 165 on August 1 to 4, 170 on August 5, 175 on August 6 and 7,
170 on August 8, then 165 on August 9 to 11, 170 on August 12, 175
on August 13 and 14, 170 on August 15 to 17, and 160 on August 18
and 19.  Predicted planetary A index is 10 on July 14, 5 on July 15
through August 2, then 10, 8 and 5 on August 3 to 5, then 8, 8, 5, 8
and 8 on August 6 to 10, 5 on August 11 through the end of the
month.  On July 12, Spaceweather.com reported, A new hyperactive
sunspot is producing M class solar flares every few hours.  This is
causing shortwave radio blackouts around all longitudes of our
planet.  If current trends continue, an X flare could be in the
offing.  See Spaceweather.com for updates.  Weekly Commentary on the
Sun, the Magnetosphere, and the Earths Ionosphere July 14 and 20,
2023 from OK1HH.  Over the past week, we were surprised by two large
groups of spots that appeared on the eastern limb of the solar disk.
The first of these, AR3363, emerged in the southeast. Although it
remained large, there was nothing significant going on.  Its
opposite was AR 3372 a few days later, which produced moderate sized
flares almost daily.  In both cases, helioseismic echoes from the
suns far side suggested that it may be the leading edge of a large
active region.  But there was no indication that these would be
areas with a diametrically different type of activity.  The images
of the two groups of spots were large enough to be observed by the
Mars rover Perseverance.  Because of Mars position, it saw them a
few days earlier than a terrestrial observer.  For the record,
Perseverance observes the Sun daily, but mainly so that it can tell
from the drop in brightness that a Martian dust storm is
approaching.  AR3372 activity is increasing, while on July 11 and 12
several M class solar flares, some with CMEs, have already occurred,
X class flare appeared to be imminent.  In particular, it was almost
certain that the Earths magnetic field activity would increase in
the following days.  The probability of magnetic storms increased
significantly as AR3372 rotated more and more toward the Earth.
There have been many papers in recent years that have looked at the
trends in ionospheric parameters over the past decades.  Although
the changes are small, they do show up in ionosonde data after much
math to eliminate solar activity and geomagnetic field activity.
These results show both positive and negative trends in the F2
region electron density, likely due to neutral atmosphere dynamics
and electrodynamics that could give regional differences.  An
interesting paper in 2008 Geophysical Research Letters modeled the
increased levels of CO2, global warming, in the atmosphere versus
the impact on the ionosphere.  Links to articles on aurora hype, a
flare video with music, a huge sunspot, and Tamitha Skovs weekly
report can be found in packet, teleprinter and internet versions of
Propagation Forecast Bulletin ARLP028.  For more information
concerning shortwave radio propagation, see
//www.arrl.org/propagation and the ARRL Technical Information
Service.
//www.arrl.org/files/file/Technology/tis/info/pdf/0209038.pdf
Instructions for starting or ending email distribution of ARRL
bulletins are at //arrl.org/bulletins Sunspot numbers were 149, 147,
167, 183, 181, 227, and 219, with a mean of 181.9.  10.7 cm flux was
157.6, 161.4, 160.5, 179.2, 190.6, 213.5, and 193.3, with a mean of
179.4.  Estimated planetary A indices were 11, 18, 8, 4, 5, 8, and
6, with a mean of 8.6.  Middle latitude A index was 11, 16, 6, 4, 6,
8, and 6, with a mean of 8.1.

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