Viewing archive of Thursday, 23 March 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Mar 23 1248 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Quiet

	10cm flux	Ap
23 Mar 2023	157	020
24 Mar 2023	155	014
25 Mar 2023	155	015

Bulletin

Solar flaring activity remained at low levels in the past 24 hours with a few low C-class flares from NOAA AR 3259 (beta) and from the newly rotated region near the south-east limb, NOAA 3262 (alpha). The remaining active regions did not produce any significant flaring activity. NOAA 3257 and NOAA 3260 underwent slight development and are now classified as magnetic type beta. NOAA AR 3256 (beta)showed slight decay as well as NOAA AR 3261 (alpha). The solar flaring activity is expected to remain at low levels over the next 24 hours.

No Earth-directed coronal mass ejections (CMEs) have been detected in the limited available coronagraph imagery.

The greater than 10 MeV GOES proton flux was at nominal levels over the past 24 hours and is expected to remain so in the next 24 hours. The greater than 2 MeV electron flux has been below the1000 pfu threshold and is expected to show some enhancements with the ongoing high speed stream arrival. The 24h electron fluence was at nominal levels and is expected to remain so over the next 24 hours and increase towards moderate levels in the days after.

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) have registered the expected arrival of a CIR in front of a high speed stream (HSS) from a negative polarity coronal hole. The solar wind velocity varied in the range of 443 to 552 km/s. The interplanetary magnetic field reached 13.6 nT with a minimum Bz of -13 nT. The B field remained predominantly in the positive sector (directed away from the Sun), but is expected to switch to the negative sector later today. The solar wind parameters over the next 24 hours are expected to remain enhanced due to the CIR and the expected arrival of a fast high speed stream later today. A possible mild glancing blow from a CME which lifted off the solar surface on March 20th was expected to arrive at Earth today, but its effects are likely to be mixed within the ongoing CIR/HSS arrival. Minor change for a glancing blow from the March 21st CME remains with possible arrival time in the late evening of March 24th. If this ejecta arrives it will be mixed within the ongoing HSS and might be difficult to resolve within the data. An equatorial negative polarity coronal hole has now merged with the southern polar coronal hole and is currently residing on the central meridian. This could lead to prolonged influence of the ongoing HSS.

The geomagnetic conditions over the past 24 hours were quiet to active. Quiet to active geomagnetic conditions are expected over the next 24 hours with increasing probability for isolated minor storms and a possible moderate storm with the ongoing CIR/HSS arrival.

Today's estimated international sunspot number (ISN): 100, based on 12 stations.

Solar indices for 22 Mar 2023

Wolf number Catania	083
10cm solar flux	159
AK Chambon La Forêt	018
AK Wingst	017
Estimated Ap	020
Estimated international sunspot number	098 - Based on 20 stations

Noticeable events summary

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

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