• ARLP048 Propagation de K7RA

    From ARRL Web site@3:633/280.2 to All on Sat Dec 3 10:57:47 2022
    SB PROP @ ARL $ARLP048
    ARLP048 Propagation de K7RA

    ZCZC AP48
    QST de W1AW
    Propagation Forecast Bulletin 48 ARLP048
    From Tad Cook, K7RA
    Seattle, WA December 2, 2022
    To all radio amateurs

    SB PROP ARL ARLP048
    ARLP048 Propagation de K7RA

    No new sunspots appeared over the past reporting week, November 24
    to 30. But sunspots were visible every day. Then on December 1
    three new sunspot groups emerged. The sunspot number rose from 12
    to 49 and the total sunspot area went from 10 to 330.

    Sunspot numbers and solar flux declined during this reporting week
    (November 24 to 30), with average daily Sunspot number dropping from
    66 to 46, and average daily solar flux from 116.5 to 108.3.

    Solar wind streams from coronal holes kept geomagnetic indicators
    active, with average daily planetary A index jumping from 5.1 to
    18.6, and middle latitude A index from 3.4 to 14.

    On Wednesday, November 30 the magnetometer at Fairbanks, Alaska
    showed the college A index at 54, the highest value over the past
    month. No doubt this produced aurora. The next day the disturbance
    continued, with collage A index at 51. These are very large
    numbers.

    The current prediction from Thursday night has solar flux reaching a
    peak of 130 this weekend, rather than 135 recently predicted. This
    is much earlier than the prediction in yesterday's ARRL Letter. We
    might also see solar flux below 100 around December 24.

    Look for flux values of 120 and 124 on December 2 and 3, 130 on
    December 4 and 5, 125 on December 6 and 7, then 120, 125, 125, 130,
    115 and 110 on December 8 to 13, 105 on December 14 to 17, 100 on
    December 18 to 23, then 95, 105 and 110 on December 24 to 26, 115 on
    December 27 to 30, and 120 on December 31, then 125 on January 1 to
    6, 2023.

    The planetary A index prediction is 20, 10, 18 and 12 on December 2
    to 5, 5 on December 6 and 7, 10 and 8 on December 8 and 9, 5 on
    December 10 to 16, 10 on December 17 and 18, 5 on December 19 to 21,
    then 20, 15, 12, and 10 on December 22 to 25, then 15, 18, 10, 18
    and 10 on December 26 to 30, 5 on December 31 through January 3,
    2023, 8 on January 4 and 5, and 5 on January 6 to 12.

    OK1HH wrote:

    "The course of solar and geomagnetic activity and therefore the
    course of shortwave propagation in the last seven days differed
    significantly from the week before.

    The solar wind speed has increased significantly (from 300 km/s to a fluctuation between 700 and 800 km/s) and the activity of Earth's
    magnetic field mostly increased.

    The changes began on 25 November at 0230 UTC when a shock wave in
    the solar wind hit the Earth. In the ionosphere we could first
    observe an increase in MUF. Further development of the disturbance
    continued only by further irregular deterioration of shortwave
    propagation.

    Enhanced solar flaring activity, including Coronal Mass Ejections
    (CMEs), did give rise to predictions of higher geomagnetic activity,
    but without the possibility of more precise timing.

    On December 1, a new larger sunspot group appeared over the
    southeastern limb of the Sun. So solar activity will not drop, but
    will probably rise again over the next few days.

    Shortwave propagation should therefore no longer deteriorate, rather
    the shortest shortwave bands will gradually open up a little better.
    In the northern hemisphere of the Earth, however, the opening
    intervals will be shorter than in recent weeks."

    Research: "Iterative Construction of the Optimal Sunspot-Number
    Series"

    https://bit.ly/3VLbTtX

    This one is spreading fast, all about hams in Montana on PBS:

    https://www.montanapbs.org/programs/ham/

    Thanks to K7SS and N7SO for the above.

    Solar wind news:

    https://bit.ly/3EVkeUW

    Send your tips, reports, observations, questions and comments to
    k7ra@arrl.net .

    For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation and the ARRL Technical Information
    Service at http://arrl.org/propagation-of-rf-signals . For an
    explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere .

    An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation . More good
    information and tutorials on propagation are at http://k9la.us/ .

    Instructions for starting or ending email distribution of ARRL
    bulletins are at http://arrl.org/bulletins .

    Sunspot numbers for November 24 through 30, 2022 were 61, 55, 60,
    56, 52, 25, and 12, with a mean of 46. 10.7 cm flux was 109.7,
    108.5, 107.1, 107.2, 107, 107.9, and 111, with a mean of 108.3.
    Estimated planetary A indices were 6, 20, 16, 15, 24, 25, and 24,
    with a mean of 18.6. Middle latitude A index was 6, 15, 12, 10, 18,
    20, and 17, with a mean of 14.
    NNNN
    /EX


    --- MBSE BBS v1.0.8 (Linux-x86_64)
    * Origin: American Radio Relay League (3:633/280.2@fidonet)
  • From ARRL Web site@3:633/280.2 to All on Sat Dec 2 09:32:00 2023
    SB PROP @ ARL $ARLP048
    ARLP048 Propagation de K7RA

    ZCZC AP48
    QST de W1AW
    Propagation Forecast Bulletin 48 ARLP048
    From Tad Cook, K7RA
    Seattle, WA December 1, 2023
    To all radio amateurs

    SB PROP ARL ARLP048
    ARLP048 Propagation de K7RA

    "GEOMAGNETIC DISTURBANCE WARNING 23/74 ISSUED AT 2321UT/29 NOVEMBER
    2023 BY THE AUSTRALIAN SPACE WEATHER FORECASTING CENTRE.

    "Several CMEs are expected to impact Earth over 30 Nov and 01 Dec.
    Two CMEs were observed on 27 Nov that were expected to arrive on 30
    Nov, followed shortly by a very mild glancing blow from a third.

    "One or possibly two halo CMEs were observed on 29 Nov which are
    Earth directed. It is likely all or some of these CMEs will combine
    on their trajectory toward Earth, making it difficult to pinpoint an
    exact arrival time, however G3-G4 geomagnetic conditions are
    possible over this period."

    Over the past reporting week, ten new sunspot groups appeared.
    Three on November 23, one each day on November 24 to 26, another on
    November 28 and three more on November 29.

    Solar numbers increased, with average daily sunspot number rising
    dramatically from 83.3 to 165.9, doubling the previous week's
    number.

    Average daily solar flux rose from 146 to 181.5.

    Geomagnetic numbers rose only slightly, with planetary A index
    changing from 10.1 to 11.6, and middle latitude numbers from 7.3 to
    7.6.

    Predicted solar flux is 166 and 162 on December 1 and 2, 158 on
    December 3 and 4, then 156, 152, 150 and 140 on December 5 to 8, 145
    on December 9 and 10, 140 on December 11 to 16, 150 on December 17,
    then 160 on December 18 to 28, then 165, 160 and 150 on December 29
    to 31, then 145 on January 1, 2024, 140 on January 2 to 4, and 145
    on January 5 and 6.

    Predicted planetary A index is 54, 22 and 10 on December 1 to 3, 16
    on December 4 and 5, 12 and 8 on December 6 and 7, 5 on December 8
    to 11, then 10 and 8 on December 12 and 13, 5 on December 14 to 17,
    then 15, 25, 8 and 5 on December 18 and 21, then 20, 10, 10, and 8
    on December 22 to 25, and 5 on December 26 to 30, then 10, 16, 12
    and 10 on December 31 through January 3, 2024, and 5 on January 4 to
    7.

    Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
    Ionosphere December 1 to 7, 2023 from OK1HH.

    "A week ago the CW portion of the CQ World Wide DX Contest was held.
    Prior to that there were several scenarios of possible developments
    during the weekend of November 25 and 26, 2023. In the end the less
    likely scenario was the one that developed. This was due to a
    relatively inconspicuous C-class solar flare observed on November
    22.

    "However, a detailed analysis of its evolution revealed that it was
    preceded by a pre-eruption, which was the first signal that a CME
    was likely to follow.

    "Further observations from satellites and radio telescopes confirmed
    the CME and measured the speed of the particle cloud. Its
    rendezvous with Earth was expected on November 24, which would have
    been bad enough for the contest. However, the particle cloud hit
    the Earth a day later. Therefore shortwave propagation improved on
    November 25 (especially in the afternoon UTC, during the positive
    phase of the disturbance), whereupon an aggravation occurred on the
    following day.

    "The maximum of solar cycle 25 is approaching. CMEs, originating
    from more energetic solar flares, or from solar plasma filament
    eruptions, are hitting Earth with increasing frequency.

    "For example, at the time of this writing, another geomagnetic
    disturbance is expected as another CME from the eruption observed on
    November 28 is expected to hit Earth on December 1 and 2.

    "In the meantime, we are observing a rather large coronal hole in
    the southeastern solar disk, which will deflate along its
    southwestern quadrant over the next week.

    "In particular, we are observing active regions to the east of it.
    This neighbourhood will result in further intensification of the
    solar wind and variations in geomagnetic field activity over the
    next week. Its predictions do exist, but they will not be
    reliable."

    I noticed that OK1HH has a packet radio address. His address is:

    Pmail: OK1HH@OK0NAG.BOH.CZE.EU

    Cycle peak in 2024? https://bit.ly/3sXwrqi

    Cycle peak in the next few months? https://bit.ly/3N7KOPG

    Predicting cycle peaks. https://bit.ly/46EKxKU

    A new long video from Dr. Tamitha Skov, WX6SWW:

    https://youtu.be/qiHtkXfZnQo

    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.

    A archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive- propagation . More good
    information and tutorials on propagation are at http://k9la.us/

    Also, check this article from September, 2002 QST:

    https://bit.ly/3Rc8Njt

    Instructions for starting or ending email distribution of ARRL
    bulletins are at http://arrl.org/bulletins

    Sunspot numbers for November 23 through 29, 2023 were 176, 184, 179,
    169, 159, 130, and 164, with a mean of 83.3. 10.7 cm flux was
    194.2, 178, 176.4, 180.2, 187.3, 183.5, and 170.6, with a mean of
    146. Estimated planetary A indices were 7, 7, 38, 10, 7, 7, and 5,
    with a mean of 10.1. Middle latitude A index was 4, 5, 18, 9, 2, 6,
    and 9, with a mean of 7.3.
    NNNN
    /EX


    --- MBSE BBS v1.0.8.4 (Linux-x86_64)
    * Origin: American Radio Relay League (3:633/280.2@fidonet)
  • From ARRL@3:633/280.2 to All on Sat Dec 14 10:15:40 2024
    SB PROP @ ARL $ARLP048
    ARLP048 Propagation de K7RA

    ZCZC AP48
    QST de W1AW
    Propagation Forecast Bulletin 48 ARLP048
    From Tad Cook, K7RA
    Seattle, WA December 13, 2024
    To all radio amateurs

    SB PROP ARL ARLP048
    ARLP048 Propagation de K7RA

    Average daily sunpsot number plummeted to 104.4.

    Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere
    for December 12, 2024 from OK1HH:


    "The high solar activity in October this year suggests that this may have
    been the peak of an 11-year cycle. This is not to say that solar activity
    will not continue to rise. On the contrary, it may well be that the first maximum of the cycle took place in October and that we can look forward to a second maximum. This could take place in 2025 or 2026 at the latest, but it will be followed by a decline.


    "Solar activity in November was lower and December's is even lower. The expected geomagnetic disturbance, predicted for 29 November, did not take
    place because the CME did not affect the Earth. However, the almost daily occurrence of moderate solar flares continued and a large flare occurred. It happened on 8 December at around 0906 UT. However, even after this eruption
    no major geomagnetic disturbance followed and the changes in ionospheric shortwave propagation were rather random."


    In December, the Sun is quieter, and large sunspot groups do not occur in its photosphere. The only major active regions we see are to the south of the
    solar equator, and their area is about half that of those seen in November. However, the active area of AR3917 is slowly getting larger and with it the likelihood of a larger flare is increasing.


    The Earth's ionosphere has been repeatedly affected in recent days by
    increased concentrations of solar-origin free electrons, which, while causing
    a slight rise in MUF, have been more pronounced in the ionosphere, causing scattering and hence attenuation, which has had a negative effect on the
    longer shortwave bands.


    More meteors are arriving at Earth these days. The swarm is called the
    Geminids and most meteors should arrive about December 14. Therefore we can observe more frequent occurrences of the sporadic E layer. In addition to the occurrences of stronger signals on the longer shortwave bands, propagation through ionospheric waveguides is more frequent. The sporadic layer may not only form one of the walls of the waveguide, but also enable its termination. Which is a good chance, for example, for QRP devotees.


    Predicted solar flux is 165 on December 13 to 15, 160 and 165 December 16 and 17, 160 on December 18 and 19, then 175, 185, and 190 on December 20 to 22,
    185 on December 23 and 24, 180 on December 25 and 26, and 180 on December 30 through January 2, 2025.


    Predicted planetary A index is 5 on January 13 and 14, 8 on January 15 and
    16, 5 on January 17 to 20, then 8 on January 29.


    Flare blasts South Africa: https://bit.ly/3Do6nJJ [ https://bit.ly/3Do6nJJ ]

    STCE Newsletter Online version: http://www.stce.be/newsletter/newsletter.php
    [ http://www.stce.be/newsletter/newsletter.php ]


    PDF version: http://www.stce.be/newsletter/pdf/2024/STCEnews20241212.pdf [ http://www.stce.be/newsletter/pdf/2024/STCEnews20241212.pdf ]


    Send your tips, reports, observations, questions and comments to
    k7ra@rrl.net. When reporting observations, don't forget to tell us which mode you were operating.


    For more information concerning shortwave radio propagation, see http://www.arrl.org/propagation [ http://www.arrl.org/propagation?utm_source=Informz&utm_medium=Email&utm_campaign=ARRL
    ] and the ARRL Technical Information Service web page at http://arrl.org/propagation-of-rf-signals [ http://arrl.org/propagation-of-rf-signals ] .


    For an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere [ http://arrl.org/the-sun-the-earth-the-ionosphere ] .


    An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation [ http://arrl.org/w1aw-bulletins-archive-propagation ] .


    More good information and tutorials on propagation are at http://k9la.us/ [ http://k9la.us/ ] .


    Check "Understanding Solar Indices" from September 2002 QST at https://bit.ly/3Rc8Njt [ https://bit.ly/3Rc8Njt ] .


    Instructions for starting or ending email subscriptions to ARRL bulletins are at http://arrl.org/bulletins [ http://arrl.org/bulletins ] .


    Sunspot numbers for December 5 through 11 2024 were 101, 103, 91, 103, 94,
    125, 114, with a mean of 104.4. 10.7 cm flux was 174.6, 177.5, 182.5, 177.7 172.5, 171.9, and 160.5 with a mean of 170.9. Estimated planetary A indices were 4, 8, 11, 7, 6, 13, and 7, with a mean of 8. Middle latitude A Index was 3, 6, 9, 6, 6, 6, 10, and 5, with a mean of 7.3.

    NNNN
    /EX

    ARRL(R) The National Association for Amateur Radio(R)
    Unsubscribe [ https://www.arrl.org/opt-in-out?utm_source=Informz&utm_medium=Email&utm_campaign=ARRL
    ]



    --- MBSE BBS v1.0.8.4 (Linux-x86_64)
    * Origin: American Radio Relay League (3:633/280.2@fidonet)