Viewing archive of Sunday, 23 March 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Mar 23 1235 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

Moderate (ISES: Major) magstorm expected (A>=50 or K=6)

Solar protons

Quiet

	10cm flux	Ap
23 Mar 2025	174	037
24 Mar 2025	171	039
25 Mar 2025	167	021

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. The largest flare was a C5.0 flare (SIDC Flare 3889) peaking on March 22 at 17:27 UTC, which was produced by SIDC Sunspot Group 412 (NOAA Active Region 4035). SIDC Sunspot Group 450 (NOAA Active Region 4036) has a Beta-Gamma magnetic configuration and is the largest and most complex region on disk but was quiet. The other regions on disk were either stable or in decay and mostly quiet. Solar flaring activity is expected to be low over the next 24 hours, with C-class flares expected and isolated M-class flares possible.

Coronal mass ejections

A faint, wide Coronal Mass Ejection (CME) directed to the south-east was observed in SOHO/LASCO-C2 from March 22 16:00 UTC, associated with a filament eruption just to the south-east of disk centre seen in SDO/AIA 304 data from 15:19 UTC March 23. This CME may have an Earth directed component and is currently being analysed. No other Earth- directed CMEs were detected in the available coronagraph data.

Coronal holes

SIDC Coronal Hole 60 (mid-latitude coronal hole with a positive polarity) began to traverse the central meridian on March 23 and the associated high speed stream is expected to arrive at Earth on March 26.

Solar wind

At the start of the period the solar wind parameters were enhanced reflecting the ongoing ICME passage before gradually reducing. The interplanetary magnetic field strength decreased from 15nT to values around 5nT. The Bz reached a minimum value of -10nT and was consistently negative. The solar wind speed reached a maximum value of 520 km/s and then decreased gradually to values around 420 km/s by the end of the period. The solar wind speed and magnetic field are expected be enhanced over the next 24 hours due to the expected high-speed stream associated with the negative polarity coronal hole which began to cross the central meridian March 19 and due to possible arrival of the CME from March 21.

Geomagnetism

In the past 24 hours the geomagnetic conditions reached minor storm conditions (NOAA Kp 5- between March 22 21:00 and March 23 00:00 UTC). Geomagnetic conditions are expected to reach active to minor storm conditions on March 23 and 24, with intervals of moderate storm conditions possible, due to the high-speed stream effects and possible CME arrival.

Proton flux levels

The greater than 10 MeV proton flux as measured by GOES-18 remained below the 10 pfu threshold and is expected to remain so over the next days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by GOES-18, remained below the 1000 pfu threshold and is expected to remain below the threshold during the next 24 hours. The 24h electron fluence was at normal levels and is expected to remain so for the next 24 hours.

Today's estimated international sunspot number (ISN): 139, based on 12 stations.

Solar indices for 22 Mar 2025

Wolf number Catania	///
10cm solar flux	178
AK Chambon La Forêt	034
AK Wingst	029
Estimated Ap	032
Estimated international sunspot number	180 - Based on 16 stations

Noticeable events summary

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

All times in UTC

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