Viewing archive of Wednesday, 22 February 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Feb 22 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
22 Feb 2023	162	011
23 Feb 2023	161	022
24 Feb 2023	160	024

Bulletin

Solar flaring activity reached high levels with an M5 flare from Catania group 94 (NOAA active region 3234) peaking at 20:17UTC following the M4 flares from that same region the days before. The region produced another M1.4 flare this morning and also several other C flares were release from the same region but also from Catania groups 89 (NOAA active region 3129) and 91 (NOAA active region 3131) and 84 (NOAA active region 3126). Catania group 89 (NOAA active region 3129) remains, although it has simplified over the period, the most complex region on disc with mixed polarity features. Catania group 93 (NOAA active region 3130) developed a trailing spot but remained relatively quiet. Further M class flaring can be expected, in particular from Catania group 94 (NOAA active region 3234).

SoHO/LASCO C2 coronagraph images show a partial halo CME towards the southwest starting 8:12UTC February 21. The angular width is up to 180 degrees. No associated on disc activity could be identified and the CME is judged to be backsided and hence have no effect on Earth. Other CMEs identified include a CME towards the northeast starting 20:48UTC related to the M5 flare and a filament eruption towards the southeast around 02:24UTC. Both are too narrow and too far off the Sun-Earth line to affect Earth.

The greater than 10 MeV proton flux was at nominal levels in the past 24 hours and is expected to remains so. The greater than 2 MeV electron flux was below the 1000 pfu threshold and is expected to remain below this threshold over the next days. The 24h electron fluence was at normal levels and is expected to be at normal levels over the next 24 hours.

A (negative polarity) extension of the southern polar coronal hole has transited the central meridian since yesterday. It may influence solar wind conditions at Earth from late tomorrow.

Solar wind conditions remained slightly enhanced. Solar wind speed increased again to over 400 km/s with peaks over 450 km/s. The magnitude of the interplanetary magnetic field showed an overall decrease to currently under 10nT. The northsouth orientation of the magnetic field was mostly northward, and the overall magnetic field orientation indicated connection to a positive sector (field away from the Sun). Slightly enhanced conditions are expected to continue with a sector change expected to occur in the next 24 hours, possibly followed by an increase in speed related to the high speed stream from the extension of the southern polar coronal hole.

Geomagnetic conditions have been mostly quiet to unsettled (local K Belgium 1-3) with the global NOAA Kp index indicating an active period at the start of the period (NOAA Kp 4). Quiet to unsettled conditions are expected for the remainder of the day and into tomorrow, with later active conditions possible in relation to the possible new high speed stream enhancements.

Today's estimated international sunspot number (ISN): 113, based on 05 stations.

Solar indices for 21 Feb 2023

Wolf number Catania	121
10cm solar flux	161
AK Chambon La Forêt	013
AK Wingst	013
Estimated Ap	013
Estimated international sunspot number	112 - Based on 14 stations

Noticeable events summary

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

All times in UTC

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