Viewing archive of Wednesday, 26 July 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Jul 26 1232 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
26 Jul 2023	169	018
27 Jul 2023	175	011
28 Jul 2023	172	006

Solar Active Regions and flaring

Solar flaring activity was moderate during the last 24 hours, with an M1 flare detected from NOAA Active Region (AR) 3380 (magnetic type Beta, Catania group 95) yesterday 21:16 UTC, an M1 flare from NOAA AR 3376 (magnetic type Beta, Catania group 86) today 04:28 UTC, and an M4 from NOAA AR 3376 today 10:37 UTC. A number of bright C-class flares was also detected in the last 24 hours, namely two C9 (from NOAA AR 3376 and 3380), a C8 (from NOAA AR 3380), and two C5 (from NOAA AR 3384 -magnetic type Beta- and NOAA AR 3376). For the next 24 hours further C-class flaring activity is expected, while isolated M-class flares remain likely.

Coronal mass ejections

No Earth-directed Coronal Mass Ejections (CME) were observed in the last 24 hours.

Solar wind

The Solar Wind (SW) conditions were affected by the predicted arrival of a glancing blow associated with the Coronal Mass Ejection (CME) of the 23 Jul. Starting from yesterday 22:00 UTC, the SW speed increased from 400 to a maximum of 560 km/s, while the total interplanetary magnetic field (Bt) increased from 5 nT to a maximum of 16 nT. The North-South component of the magnetic field (Bz) varied between -13 and 10 nT since the arrival of the disturbance. The interplanetary magnetic field phi angle was almost exclusively directed towards the Sun during the past 24 hours. The effects of the glancing blow are expected to slowly wane in the next 24 hours.

Geomagnetism

A geomagnetic disturbance took place yesterday at 22:00 UTC and resulted to minor storm levels globally (NOAA Kp 5-) yesterday at 21:00-24:00 UTC and today at 03:00-06:00 UTC. Before the arrival the global levels were at a quiet level (NOAA Kp 2 to 2+), while for the rest of the time today they were active (NOAA Kp 4- to 4+). At a local level the geomagnetic conditions reached the active level (K BEL 4) yesterday at 21:00-24:00 UTC, while before the event they were at quiet to unsettled levels (K BEL 2 to 3), and today they remain at unsettle levels (K BEL 3). As the disturbance is expected to be short-lived, the geomagnetic levels are expected to be up to active levels globally and unsettled levels locally for the next 24 hours.

Proton flux levels

The greater than 10 MeV proton flux was above the background level and raised as high as 3 pfu during the last 24 hours. However, it should be noted that this is well below the 10 pfu threshold level. For the next 24 hours the 10 MeV proton flux is expected to continue its drop and reach background levels.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold and is expected to remain below this threshold during the next 24 hours. The 24h electron fluence was at nominal levels and is expected to remain so.

Today's estimated international sunspot number (ISN): 158, based on 15 stations.

Solar indices for 25 Jul 2023

Wolf number Catania	///
10cm solar flux	169
AK Chambon La Forêt	024
AK Wingst	009
Estimated Ap	011
Estimated international sunspot number	135 - Based on 27 stations

Noticeable events summary

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

All times in UTC

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