• Weekly Highlights of Solar and Geomagnetic Activity, 12 - 18 September

    From SWPC.Webmaster@noaa.gov@21:1/5 to All on Mon Sep 19 13:00:08 2022
    XPost: rec.radio.amateur.space, rec.radio.shortwave, rec.radio.info

    :Product: Weekly Highlights and Forecasts
    :Issued: 2022 Sep 19 0622 UTC
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    # Weekly Highlights and Forecasts
    Highlights of Solar and Geomagnetic Activity
    12 - 18 September 2022

    Solar activity reached high levels this week, with six M-class
    flares observed during the period. Region 3098 (N18, L=053,
    class/area Ehc/860 on 14 Sep) produced the largest event, an M7.9
    flare at 16/0949 UTC. This was followed at 16/1559 UTC by an M6.2/Sn
    flare from the same region. The remaining M flares, all associated
    with Region 3098, ranged from M1.1 to M2.6. Of the 11 regions
    numbered, Region 3098 was the largest, most magnetically complex,
    and most productive. It was responsible for 39 C-class flares in
    addition to the M-flares described above. Throughout the week there
    were several CMEs but none were Earth-directed.

    No proton events meeting alert criteria were observed at
    geosynchronous orbit, although the 10 MeV proton flux was slightly
    elevated above background levels, mostly likely in response to an
    event on the far side of the sun.

    The greater than 2 MeV electron flux at geosynchronous orbit was
    elevated at the beginning of the week but subsquently fell below the
    1000 pfu threshold after the arrival of a transient feature on the
    14th described below. It remained at normal-moderate levels for the
    remainder of the week.

    Geomagnetic field activity ranged from quiet to active levels. The
    active conditions were observed on the synoptic periods straddling
    14-15 Sept and associated with influences from an unattributed
    transient feature. The disturbed conditions were preceded by a 30 nT
    sudden impulse observed at 2315 UTC (Boulder Magnetometer) on
    September 14th. An extended quiet period followed until 18 September
    when conditions rose to unsettled levels in response to coronal hole
    high speed stream influences. Solar wind speed in this coronal hole
    reached the mid 500 km/s range.

    Forecast of Solar and Geomagnetic Activity
    19 September - 15 October 2022

    Solar activity is expected to be low with a chance for M-class
    (R1-R2, Minor-Moderate) flares on 19 Sep - 02 Oct as old Region 3089
    (S22, L=194) returns. This region was previously responsible for 5
    M-class events and continues to be active based on imagery of the SE
    limb. Region 3098 is expected to return around 29 September,
    bringing the potential for a continued chance of M-class flare
    activity through the end of the period.

    No proton events are expected at geosynchronous orbit.

    The greater than 2 MeV electron flux at geosynchronous orbit is
    expected to reach high levels on 20-23 September and 01-11 October
    in response to CH HSS influences.

    Geomagnetic field activity is likely to reach minor (G1) storm
    levels on the 22-23 Sep with the arrival of a HSS associated with a
    positive polarity coronal hole. Another positive polarity coronal
    hole and HSS are expected to bring minor (G1) to moderate (G2) storm
    conditions on 30 Sep - 03 Oct.

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