Viewing archive of Sunday, 23 July 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Jul 23 1240 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
23 Jul 2023	174	012
24 Jul 2023	170	009
25 Jul 2023	170	010

Solar Active Regions and flaring

Solar flaring activity over the past 24 hours was at low levels. The largest flare was a C9.9-flare, with peak time 04:54 UTC on July 23, produced by NOAA AR 3373 (beta), which is one of the most complex regions on disk but is also starting to decay. There are currently 7 numbered active regions on the visible disk including new numbered active region NOAA AR 3380 which has started to rotate on disk in the southern hemisphere. NOAA AR 3372 (beta), NOAA AR 3376 (beta) and NOAA AR 3379 (beta) are decaying. NOAA AR 3378 (alpha) and NOAA AR 3377 (beta) remained stable. 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

In SDO/AIA 304 a filament was observed erupting in the north-east quadrant around 16 UTC on July 22 producing an on-disk dimming. However, no clear Coronal Mass Ejection (CME) signature has been identified as this was quickly followed by two eruptions in the north-east quadrant obscuring the CME. In LASCO/C2 coronagraph data from 21:24 UTC on July 22 two eruptions were seen to the east and the north-east likely associated with these two eruptions near to NOAA AR 3379. The filament eruption is still being analysed as it may have an Earth directed component due to the source location it may have an Earth directed component. The CMEs to the north and north east are not expected to impact Earth. The previously mentioned CME associated with the M3.2-flare on July 22 is not expected to arrive at Earth.

Coronal holes

The negative polarity coronal hole is still transiting the central meridian in the northern hemisphere. Two small positive polarity mid latitude coronal holes one in the north and one in the south are approaching the central meridian.

Solar wind

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) reflected the waning influence of the ICME. The solar wind velocity fluctuated between 400 km/s to 480 km/s. The interplanetary magnetic had a maximum value of 8 nT going to 6 nT by the end of the period. Bz had a minimum value of -5 nT. The magnetic field orientation was predominantly in the negative sector (field directed towards from the Sun). Slow solar wind conditions are expected in the next two days with small enhancements possible due to the High-Speed Stream (HSS) associated with a negative polarity coronal hole.

Geomagnetism

The geomagnetic conditions over the past 24 hours were quiet (NOAA KP = 2 and K-Bel = 2). Quiet to unsettled conditions are expected over the next two days.

Proton flux levels

The greater than 10 MeV proton flux was at background levels over the last 24 hours and 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-16 and GOES-18 stayed below the 1000 pfu alert threshold and is currently at background levels. The greater than 2 MeV electron flux is not expected to cross the threshold 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): 135, based on 08 stations.

Solar indices for 22 Jul 2023

Wolf number Catania	///
10cm solar flux	174
AK Chambon La Forêt	011
AK Wingst	010
Estimated Ap	010
Estimated international sunspot number	136 - Based on 20 stations

Noticeable events summary

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

All times in UTC

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