Viewing archive of Saturday, 22 July 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Jul 22 1231 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
22 Jul 2023	170	013
23 Jul 2023	165	011
24 Jul 2023	160	012

Solar Active Regions and flaring

Solar flaring activity over the past 24 hours was at moderate levels. The largest flare was a M3.2-flare, with peak time 03:37 UTC on July 22, produced by NOAA AR 3372. There are currently 5 numbered active regions on the visible disk. NOAA AR 3373 is the most magnetically complex and also produced a M1.0-flare, with peak time 04:16 UTC on July 22. NOAA AR 3372 and NOAA AR 3376 are decaying and NOAA AR 3377 and NOAA AR 3379 are stable. NOAA AR 3374 has decayed into a plage region. The solar flaring activity is likely to remain at low levels over the coming days with C-class flares expected, M-class flares possible and a low chance for isolated X-class flaring.

Coronal mass ejections

A Coronal Mass Ejection (CME) was observed in LASCO/C2 coronagraph data from 04:12 UTC on July 22 UTC to the west. The CME is associated with an eruption behind the east limb and is not expected to be Earth directed. Possibly a CME erupted associated with the M3.2-flare, with peak time 03:37 UTC on July 22 but it has been obscured by the brighter back sided CME. Investigation ongoing. No other Earth directed CMEs have been detected.

Coronal holes

A negative polarity high latitude coronal hole is continuing to transition the central meridian.

Solar wind

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) registered signatures of a ICME arrival. A jump was observed in the solar wind parameters at 19:20 UTC on July 21. The solar wind velocity jumped from 378 km/s to 405 km/s continued to increase up to 440 km/s. The interplanetary magnetic field jumped from 6 nT to 9 nT reaching a maximum value of 15 nT. The Bz reached a minimum of -15 nT. The solar wind density jumped from 6.43 ppc to 13.52 ppc and reached a maximum of 17.62 ppc. This may mark the expected arrival from the CME from July 18. After decreasing slightly, the solar wind speed rose to speeds around 420 km/s. Continued enhanced solar wind conditions are expected in the next two days due to ongoing ICME and possible High Speed Stream (HSS) influence.

Geomagnetism

The geomagnetic conditions over the past 24 hours were quiet to active (NOAA KP = 4 and K-Bel = 4) with an active period between 21:00 on July 21 and 02:00 UTC on July 22 associated with the ICME arrival. Quiet to unsettled conditions are expected with possible active intervals over the next day. Returning to quiet conditions on July 23.

Proton flux levels

The greater than 10 MeV proton flux was gradually continued to decrease from enhanced to background levels while remaining under the 10 pfu threshold over the last 24 hours. The proton flux is expected to remain at background levels in the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux measured by GOES-18 reached the 1000 pfu alert threshold but returned to background levels. The greater than 2 MeV electron flux is not expected to cross the threshold again in the next 24 hours. The 24h electron fluence was at nominal levels and is expected to remain at nominal levels in the next 24 hours.

Today's estimated international sunspot number (ISN): 134, based on 12 stations.

Solar indices for 21 Jul 2023

Wolf number Catania	///
10cm solar flux	173
AK Chambon La Forêt	019
AK Wingst	014
Estimated Ap	014
Estimated international sunspot number	139 - Based on 23 stations

Noticeable events summary

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

All times in UTC

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