Viewing archive of Wednesday, 20 April 2022

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2022 Apr 20 1231 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
20 Apr 2022	149	010
21 Apr 2022	149	008
22 Apr 2022	145	007

Bulletin

Solar flaring activity was high. The strongest flaring was from Catania group 76 (NOAA active region AR 2992) located at the western limb. It produced 2 M flares and one X flare. The strongest were the M7.2 flare peaking at 1:36 UT and the X2.2 flare peaking at 3:57 UT. Further flaring was from the Catania sunspot groups 81 and 82 (NOAA AR 2993 and 2994) in the northeast including two minor M1 flares from Catania sunspot group 82 (NOAA AR 2994). The regions in the north-east continue to display a complex structure of the photospheric field, with opposite polarity flux concentrations near the leading spot of Catania sunspot group 81 (NOAA AR 2993) and near the trailing spot of Catania sunspot group 82 (NOAA AR 2994). Further flux emergence in between the two regions is observed. Catania sunspot group 84 (NOAA AR 2995) was a strong unipolar region but seems to be developing a small trailing spot now. Other regions on disc were insignificant (vanished or were in decay). Overall flares at M level are likely with also a very significant chance for X flares, from the regions in the east.

The two largest flares, the M7.2 and the X2.2 flares, were associated with EUV waves and off-disc dimmings. And a type II radio burst was associated with the X flare. SoHO/LASCO coronagraph images show two associated CMEs towards the west from 2:00UT and 4:12UT onwards in C2 field of view. A filament eruption can also be seen in SDO 304 images around 19UT towards the south-east and an associated CME is seen in SoHO/LASCO coronagraph images around 20:12UT. None of these appears to be wide enough to expect any arrival at Earth.

The greater than 10 MeV proton flux was at background levels. There is some limited risk of a proton event (a combination of a decreasing risk from Catania group 76 (NOAA active region AR 2992) as it moves further away at the far side, and an increasing risk from Catania sunspot groups 81 and 82 (NOAA AR 2993 and 2994) moving towards the west). The greater than 2 MeV electron flux reached again above the 1000 pfu alert threshold at the diurnal maximum. The 24h electron fluence reached moderate levels and is expected to be normal to moderate, following the high speed stream Solar wind conditions in the previous days. A decreasing trend is expected to set in from from after tomorrow.

A return to slow Solar wind conditions was observed. Solar wind speed decreased to 400 km/s. The interplanetary magnetic field was around 5nT with a variable and unremarkable north-south component, and the orientation indicating connection to a positive polarity sector. There were no signs of a possible glancing blow of the CME of the morning of April 17, and it is not expected anymore. Slow solar wind conditions are expected over the next days.

Geomagnetic conditions were quiet to unsettled (NOAA Kp 0-3 and local K Belgium 1-3). Geomagnetic conditions are expected to be quiet with isolated unsettled periods.

Today's estimated international sunspot number (ISN): 093, based on 25 stations.

Solar indices for 19 Apr 2022

Wolf number Catania	123
10cm solar flux	135
AK Chambon La Forêt	011
AK Wingst	008
Estimated Ap	007
Estimated international sunspot number	090 - Based on 31 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

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