• Weekly Highlights of Solar and Geomagnetic Activity, 28 March - 03 Apri

    From SWPC.Webmaster@noaa.gov@21:1/5 to All on Mon Apr 4 13:00:12 2022
    XPost: rec.radio.amateur.space, rec.radio.shortwave, rec.radio.info

    :Product: Weekly Highlights and Forecasts
    :Issued: 2022 Apr 04 0517 UTC
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    # Weekly Highlights and Forecasts
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    Highlights of Solar and Geomagnetic Activity
    28 March - 03 April 2022

    Solar activity reached high levels at 30/1737 UTC due to an X1
    flare, the largest of the period, from Region 2975 (N13, L=088,
    class/area Dkc/330 on 30 Mar). This event was associated with Type
    II (estimated speed of 1,424 km/s) and Type IV radio sweeps, 10 cm
    radio burst (540 sfu), and a CME that after modeling did not appear
    to contain an Earth-directed component. Region 2975 was the most
    active and magnetically complex region on the disk throughout the
    period. It was responsible for an M4 flare at 28/1129 UTC, with
    associated Type II radio sweep and a partial halo/asymmetric CME.
    Region 2975 produced a second M-flare, an M1/Sn at 28/2059 UTC, also
    with Type II activity and a full halo/asymmetric CME. Subsequesnt
    analysis and modeling indicated Earth-directed transients from both
    events with speeds of 667 km/s and 841 km/s respectively. The second
    and faster CME was forecast to catch up and combine with the first
    transient from the M4 event. The combined arrival of both events at
    the magnetosphere was forecasted for early on 31 Mar. Region 2975
    was responsible for an M9/1b flare at 31/1835 UTC, with associated
    Type II and Type IV radio sweeps, 10 cm radio bursts and a CME that
    was not determined to be Earth-directed. Region 2975 produced four
    additional M-flares during the period: an M2/2n flare at 29/0111
    UTC; an M1 flare at 29/2152 UTC; an M2 flare at 02/0256 UTC; and an
    M4/1n flare at 02/1744 UTC. Region 2976 (N15, L=068, class/area
    Eko/550 on 30 Mar) produced an M3/Sn flare at 02/1355 UTC. Region
    2974 (S18, L=090, class/area Cso/90 on 23 Mar) produced an M1/Sf
    flare at 29/0158 UTC.

    Four proton events were observed during the period. The first event
    was a 10 MeV integral flux event that exceeded 10 pfu. It began at
    28/1325 UTC, reached a maximum of 18.7 pfu at 28/1450 UTC, and ended
    at 28/2115 UTC. The second event was a 100 MeV event that exceeded 1
    pfu that began at 28/1245 UTC, reached a maximum flux of 1 pfu at
    28/1325 UTC, and ended at 28/1455 UTC. The third event was a 10 MeV
    integral flux event that excedded 10pfu. This event began at
    31/0620, reached a maximum flux of 10.6 pfu at 31/0630 UTC, and
    ended at 31/0720 UTC. The last proton event was a 10 MeV integral
    flux event that exceeded 10 pfu. This event began at 02/1430 UTC,
    reached a maximum flux of 32 pfu at 02/1600 UTC, and ended at
    03/0005 UTC.

    The greater than 2 MeV electron flux at geosynchronous orbit reached
    high levels on 03 Apr with a peak flux of 2,600 pfu at 03/1505 UTC.
    This activity was in response to elevated solar wind speeds from the
    28 Mar CMEs. Electron flux reached moderate levels on 28 Mar - 02
    Apr.

    Geomagnetic field activity reached active levels late on 30 Mar and
    G1 (Minor) storm levels early on 31 Mar in response to a pair of
    CMEs that left the solar disk on 28 Mar. Solar wind speed
    stair-stepped from ~410 km/s to 500 km/s and then later 600+ km/s
    after arrival. Total field peaked at 23 nT while Bz briefly dropped
    as low as -12 nT. Active levels were observed on 01-03 Apr with G1
    (Minor) storms observed on 02 Apr as these transient features
    persisted and later combined with a negative-polarity CH HSS. Active
    levels were observed on 28 Mar due to positive polarity CH HSS
    influence and quiet conditions prevailed on 29 Mar on the days
    preceeding the dual CME arrival.

    Forecast of Solar and Geomagnetic Activity
    04 April - 30 April 2022

    Solar activity is likely to be moderate (R1-R2, Minor-Moderate) with
    a chance for X-class flaring on 04 Apr. M-class flaring probability
    decreases to a slight chance on 05-06 Apr as Region 2975 rotates
    around the west limb. These probabilities are anticipated on 14-27
    Apr with the return of Region 2975. Very low to low activity is
    expected on Apr 07-13 and 28-30 Apr.

    The greater than 10 MeV proton flux at geosynchronous orbit may
    increase above the 10 pfu threshold (S1-Minor) on 04 Apr if Region
    2975 produces another significant eruption. A return to background
    levels is anticipated for the remainder of the outlook period.

    The greater than 2 MeV electron flux at geosynchronous orbit is
    expected to reach high levels on 04-07 Apr in response to persistent
    combined CME/CH HSS influence.

    Geomagnetic field activity is expected to reach active levels on 04,
    11, 23, 29-30 Apr and unsettled levels on 05, 12, 20-21, 24-25 Apr
    due to recurrent CH HSS effects. Quiet conditions are anticipated
    for the remainder of the outlook period.

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