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Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Apr 01 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
01 Apr 2023	125	016
02 Apr 2023	123	006
03 Apr 2023	125	004

Bulletin

Over the past 24 hours, the solar flaring activity has been at low levels with currently only 5 numbered active regions observed on the visible side of the solar disk. A total of 6 GOES C-class flares have been reported. The flaring activity overall originated from the active regions that rotated behind the West solar limb over the past 24 hours. The strongest flare reported was a C9.8 class flare originating from behind the West solar limb, most likely originating from NOAA AR 3257 with a peak time at 20:57UT on March 31. From the same region also a C6.8 originated with peak time at 03:28 UT and an associated coronal mass ejection (CME) has been observed by SOHO/C2 and C3. The CME is not expected to impact Earth. All current active regions on the visible side of the solar disk have a very simple configuration of the phosphoric magnetic field (alpha and beta), some are in the process of fading. We expect low flaring activity levels to persist with C-class flares expected.

During the last 24 hours there were no potentially Earth-directed CMEs detected in the available coronagraph observations.

The greater than 10 MeV proton flux was at nominal levels over the past 24 hours and we expect this to remain so over the next day. As expected the greater than 2 MeV electron flux has passed the threshold over the past 24 hours, starting at about 18:00 UT and it is currently still above the threshold. We expect the 2 MeV electron flux to remain around the threshold for the next 24 hours. The 24h electron fluence was at normal levels over the past 24 hours. As a result of the increase in the 2 MeV electron flux, we expect the fluency to increase over the next 24 hours.

From about 14:00 UT on March 31, the solar wind speed has gradually decreased from values of about 520 km/s to values of about 440 km/s. Starting at about 03:00 UT on April 1, the solar wind speed has been gradually increasing once again up to values of about 550 km/s at present. The magnitude of the interplanetary magnetic field was about 4-5 nT during the last 24 hours. We expect the solar wind speed to once again start a gradual decline over the next 24 hours. Two small, negative polarity coronal holes have been observed at the centre of the solar disk. We do not expect a strong impact of the solar wind originating from these coronal holes.

During the last 24 hours, the geomagnetic conditions were quiet to unsettled. K and Kp indices between 1 and 4 and between 1 and 4- have been reported in the local station at Dourbes and NOAA, respectively. Geomagnetic conditions are expected to stay unsettled over the next 24 hours.

Today's estimated international sunspot number (ISN): 059, based on 06 stations.

Solar indices for 31 Mar 2023

Wolf number Catania	095
10cm solar flux	129
AK Chambon La Forêt	023
AK Wingst	023
Estimated Ap	022
Estimated international sunspot number	079 - Based on 13 stations

Noticeable events summary

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

All times in UTC

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