Viewing archive of Friday, 12 May 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 May 12 1237 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
12 May 2023	157	016
13 May 2023	152	013
14 May 2023	150	013

Bulletin

Solar flaring activity was at moderate levels over the past 24 hours. The largest flare of the period was an M1.8 flare, peaking at 18:29 UTC May 11, associated with NOAA AR 3294. NOAA AR 3296 and NOAA AR 3297 decayed over the period. New sunspots began to develop east of NOAA 3301. The solar flaring activity is expected to be at low levels over the next 24 hours with C-class flares likely and M-class flares possible.

On May 11, there were a number of CMEs observed from the west limb. Some of which were associated with the flaring activity of NOAA AR3294. The first of which was first seen in SOHO/LASCO-C2 data at 09:48 UTC, associated with the M2.1 flare reported yesterday. The bulk of the CME is directed to the west but a glancing blow at Earth may be possible from May 14. Another CME to the west can be seen from 19:00 UTC, likely associated to the M1.9 flare, this appears narrower but any possible Earth directed component would likely merge with the first CME. A filament eruption was observed from the south west quadrant, first seen in SDO/AIA 304 at 04:44 UTC. An associated faint CME can be seen in SOHO/LASCO-C2, however we are awaiting further imagery to determine if this could have an Earth directed component.

The greater than 10 MeV proton flux continued to gradually decrease on May 11 and was below the 10pfu. It is expected that the proton flux will be below this threshold for the next days. The greater than 2 MeV electron flux was below the 1000 pfu threshold and is expected to increase slightly and will likely cross this threshold over the next days. The 24h electron fluence was at nominal levels and is expected to be at nominal to moderate levels over the next 24 hours.

The solar wind conditions (ACE and DSCOVR) were stable for the majority of the period, with a total interplanetary magnetic field strength of around 6nT and solar wind speed around 510 km/s. A small shock was observed in the solar wind at 05:48 UTC May 12. At this time the speed increased from 496 to 552 km/s and the magnetic field increased from 6 to 10 nT. Bz however was mostly positive with a minimum value of -5 nT. This was likely related to the CME from May 09. The interplanetary magnetic field was predominantly in the positive sector (directed away from the Sun). The solar wind conditions are expected to continue to be elevated on May 12 due to the ICME passage. From May 13, we expect the solar wind speed and magnetic field to gradually decrease. Further enhancements may then be possible from May 14, due to the multiple CMEs observed on May 11.

The geomagnetic conditions reached active conditions (NOAA KP = 4 and K bel =4). Unsettled to active conditions are expected for the rest of May 12, returning to quiet to unsettled conditions on May 13.

Today's estimated international sunspot number (ISN): 133, based on 10 stations.

Solar indices for 11 May 2023

Wolf number Catania	218
10cm solar flux	163
AK Chambon La Forêt	///
AK Wingst	011
Estimated Ap	010
Estimated international sunspot number	154 - Based on 22 stations

Noticeable events summary

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

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