• ARLP031 Propagation de K7RA

    From ARRL Web site@21:1/5 to All on Fri Aug 5 23:57:48 2022
    XPost: rec.radio.shortwave, rec.radio.info

    SB PROP @ ARL $ARLP031
    ARLP031 Propagation de K7RA

    ZCZC AP31
    QST de W1AW
    Propagation Forecast Bulletin 31 ARLP031
    From Tad Cook, K7RA
    Seattle, WA August 5, 2022
    To all radio amateurs

    SB PROP ARL ARLP031
    ARLP031 Propagation de K7RA

    Solar activity continued to decline this week, with average daily
    sunspot number dropping from 91.1 to 36.6 and average solar flux at
    95.7, down from 107.6 the week prior.

    Thursday's sunspot number was above the average for the previous
    seven days at 52. Solar flux on Thursday was above the previous
    seven day average at 108.8. The 2300 UTC flux was 111.3.

    We've not seen lower values since mid-April in bulletin ARLP015 with
    average sunspot number at 34.4, and the end of February in ARLP008
    with average solar flux at 95.4.

    To track solar cycle 25 progress, I like to compare current averages
    against the same numbers from last year. In the 2021 version of
    ARLP031, average daily sunspot numbers were 33.1 (lower by 3.5 from
    this week's report), and average solar flux was 83, down 12.7 from
    the current average.

    The lower activity was quite noticeable over the past week on 10 and
    12 meters, but there must still be some daily sporadic-E, from what
    I've seen on an email list devoted to 10 meter propagation beacons.
    I have one myself, K7RA/B transmitting CW from CN87uq on 28.2833
    MHz.

    The outlook from the USAF space weather group shows a meager
    forecast for solar flux, this one from forecasters Hoseth and
    Strandness on Thursday.

    The latest forecast is a bit more optimistic than the Wednesday
    version, with solar flux at 112 instead of 100 for the next few
    days.

    Predicted solar flux is 112 on August 5 to 7, 110 on August 8 and 9,
    112 on August 10, 114 on August 11 and 12, 98 on August 13 and 14,
    100 on August 15 and 16, 98 on August 17 and 18, then 96, 96 and 98
    on August 19 to 21, 96 again on August 22 and 23, 92 on August 24 to
    28, 90 and 92 on August 29 and 30, 94 on August 31 through September
    1, 96 on September 2 and 3, then 98 on September 4 to 10, and 100 on
    September 11 and 12.

    Predicted planetary A index 5 on August 5, 8 on August 6 and 7, then
    5, 14, 12, 18 and 12 on August 8 to 12, 5 on August 13 to 16, then
    22 on August 17, 15 on August 18 and 19, 8 on August 20 and 21, 5 on
    August 22 to 25, then 10 and 12 on August 26 and 27, 5 on August 28
    and 29, then 12 and 10 on August 30 and 31, 5 on September 1 to 6, 8
    on September 7 to 8, and 5 on September 9 to 12.

    OK1HH wrote:

    "Throughout the period, solar activity was low, the Earth's magnetic
    field quiet to unsettled. Shortwave propagation conditions were
    average to slightly below average.

    An interesting phenomenon for observers may have been a giant solar
    prominence - a loop of plasma on the sun's eastern limb.

    But even more interesting was the report of a farside sunspot. So
    big it is changing the way the sun vibrates. Helioseismic maps
    reveal its acoustic echo not far behind the sun's southeastern limb!
    The sunspot will turn to face Earth a few days from now."

    Space Weather Woman Dr. Tamitha Skov, WX6SWW put out a new forecast
    on July 29.

    https://youtu.be/F3T4VI1VSPc

    Recently Dr. Skov sent this out (I edited) to her Patreon
    subscribers:

    "This week the Sun is a mixed bag of active regions, coronal holes
    and solar eye candy. Although we aren't expecting any strong
    storming at Earth, we do have a big-flare player in view and are
    expecting some fast solar wind over the next few days (and then
    again sporadically next week). This might give aurora photographers
    at high latitudes a brief show, but it likely wont be much, if any
    better than the weak shows we got this past week.

    Solar flux is finally back into the triple digits, which means
    decent radio propagation again on Earth's day side and along with
    the reasonably low risk for radio blackouts, amateur radio operators
    as well as GPS users should enjoy better than average signal
    reception (and transmission)."

    I like to watch this link to see what might be coming over the next
    few days on our Sun:

    https://stereo.gsfc.nasa.gov/

    On Thursday night over on the left I am seeing lots of white
    splotches, perhaps indicating areas of magnetic complexity and maybe
    sunspots arriving soon. The horizon is at -90 degrees.

    Although the STEREO mission has survived way past the initial design
    life, one of the probes has been gone for a few years, leaving us a
    very limited view of the sun.

    I would love to see a replacement probe, which I have heard might
    cost twenty-million dollars. Or perhaps a brand new advanced
    design? Perhaps one of our domestic billionaires fascinated by
    space flight could make this happen.

    Newsweek has solar news:

    https://bit.ly/3oZmYcB

    Large sunspot emerging:

    https://bit.ly/3oXVMuQ

    Ginormous:

    https://bit.ly/3QpmU1A

    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 July 28 through August 3, 2022 were 50, 40, 27,
    39, 32, 31, and 37, with a mean of 36.6. 10.7 cm flux was 93, 90.8,
    94.3, 95.4, 97.8, 98.8, and 99.9, with a mean of 95.7. Estimated
    planetary A indices were 7, 4, 7, 11, 8, 9, and 8, with a mean of
    7.7. Middle latitude A index was 9, 6, 8, 12, 8, 10, and 7, with a
    mean of 8.6.
    NNNN
    /EX

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  • From ARRL Web site@21:1/5 to All on Fri Aug 4 20:16:40 2023
    XPost: rec.radio.shortwave, rec.radio.info

    SB PROP @ ARL $ARLP031
    ARLP031 Propagation de K7RA

    ZCZC AP31
    QST de W1AW
    Propagation Forecast Bulletin 31 ARLP031
    From Tad Cook, K7RA
    Seattle, WA August 4, 2023
    To all radio amateurs

    SB PROP ARL ARLP031
    ARLP031 Propagation de K7RA

    The Australian Space Weather Forecasting Centre issued a geomagnetic disturbance warning at 0233 UTC on August 3.

    "Two recent coronal mass ejections (CMEs) are expected to impact
    Earth on UT day 05-Aug, with the second possibly arriving early
    06-Aug. G0-G1 geomagnetic conditions may be expected on 05-Aug, with
    a chance for isolated periods of G2 towards the end of the UT day on
    05-Aug. Geomagnetic storm conditions may persist over 06-Aug."

    Solar activity was up during this reporting week, July 27 through
    August 2.

    Average daily sunspot numbers increased from 128.1 to 154.3, but
    average daily solar flux was about the same as last week, moving
    just from 172.2 to 173.

    Geomagnetic indicators were quiet, with average daily planetary A
    index shifting from 11 to 8.3, while middle latitude numbers went
    from 11.1 to 9.3.

    Predicted solar flux is 160 on August 4-5, 162 on August 6, 164 on
    August 7-8, 162 and 160 on August 9-10, 168 on August 11-12, 170 on
    August 13-16, 172 on August 17-18, then 170 and 168 on August 19-20,
    170 on August 21-22, 172 on August 23, and 170 on August 24-27, then
    165 on August 28-31, then 168, 170, 168, 165, 168, and 165 on
    September 1-6, 168 on September 7-8, and 170 on September 9-12.

    Predicted planetary A index 15, 26, 15 and 8 on August 4-7, 5 on
    August 8-10, 8 on August 11-12, 5 on August 13-25, then 12 and 10 on
    August 26-27, and 5 on August 28-31, 12 and 10 on September 1-2, 5
    on September 3-5, 10 on September 6, 8 on September 7-8, and 5 on
    September 9-17.

    No report from OK1HH this week as he vacations in the mountains in
    Europe.

    See https://bit.ly/44Tw4e2 for an image of him on vacation
    previously.

    Here are reports from two of his colleagues at Czech observatories.

    "Solar activity forecast for the period August 4-10, 2023.

    Activity level: mostly low to moderate
    X-ray background flux (1.0-8.0 A): in the range C1.1-C2.5
    Radio flux (10.7 cm): a fluctuation in the range 155-185
    Events: class C (2-15/day), class M (0-3/day), class X (0-2/period),
    proton (0-1/period)
    Relative sunspot number (Ri): in the range 124-220

    Martina Pavelkova RWC Prague, Astronomical Institute, Solar Dept.,
    Ondrejov, Czech Republic"

    "Geomagnetic activity forecast for the period August 4-10, 2023

    Quiet: Aug 3, 5-8
    Unsettled: Aug 4-5, 9-10
    Active: Jul 10
    Minor storm: 0
    Major storm: 0
    Severe storm: 0

    Next week, we do not expect any storming event. Currently we expect
    quiet to unsettled conditions. The most unsettled episode is
    expected at the end of current forecast period, August 9-10.

    Tomas Bayer RWC Prague Institute of Geophysics of the ASCR, Prague
    Department of Geomagnetism Budkov observatory (BDV)"

    Look at all the sunspots on August 3! https://bit.ly/45fC1lE

    CMEs: https://bit.ly/3ORBO2J https://bit.ly/3qg2aSe

    In an exchange with Carl Luetzelschwab, K9LA and OK1HH, Carl
    commented, "Many papers show that climate change has affected the
    ionosphere. Is the change enough to actually notice it in
    predictions and in on-the-air operations? To answer the prediction
    aspect, I looked at Millstone Hill (Massachusetts) foE and foF2
    ionosonde data at 1700 UTC (around local noon) for October 1998 (V1
    smoothed sunspot number = 70) and January 2023 (V2 smoothed sunspot
    number = 114, which gives a V1 number of 80). The data is 24 years
    apart, and I figured a trend due to climate change might show up if
    there was one. I compared the ionosonde data to what VOACAP
    predicted for those two months."

    His conclusion? No effect.

    V1 and V2 refer to the new and old version sunspot numbers,
    explained here: https://www.sidc.be/SILSO/newdataset

    This relates to the statement in the OK1HH report in http://arrl.org/w1aw-bulletins-archive/ARLP027/2023 last month about
    global changes affecting propagation.

    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.

    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 .

    Also, check this article from September, 2002 QST:

    https://www.arrl.org/files/file/Technology/tis/info/pdf/0209038.pdf

    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 July 27 through August 2, 2023 were 154, 148,
    147, 139, 197, 160, and 135, with a mean of 154.3 10.7 cm flux was
    165.3, 168.2, 178.6, 174.4, 177.1, 174.7, and 172.9, with a mean of
    173. Estimated planetary A indices were 7, 6, 9, 9, 6, 9, and 12,
    with a mean of 8.3. Middle latitude A index was 7, 5, 8, 18, 8, 9,
    and 10, with a mean of 9.3.
    NNNN
    /EX

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