Viewing archive of Friday, 28 July 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Jul 28 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
28 Jul 2023	178	005
29 Jul 2023	175	005
30 Jul 2023	172	004

Solar Active Regions and flaring

Solar flaring activity was moderate during the last 24 hours, with an M1 flare produced by NOAA Active Region (AR) 3388 (magnetic type Beta, Catania group 1) yesterday 22:34 UTC. NOAA AR 3376 (magnetic type Beta, Catania group 86) produced by far the largest number of C-class flares in the last 24 hours with four of them being brighter than C5.0, and one of the brightest, a C7 today 01:09 UTC. NOAA AR 3380 (magnetic type Beta, Catania group 95) produced the third brightest flare of the last 24 hours, a C7 today at 01:46 UTC. NOAA 3387 (magnetic type Alpha, Catania group 3) also produced a C5 flare yesterday at 22:04 UTC. For the next 24 hours the number of C-class flares is expected to drop as NOAA 3376 will rotate out of Earth's view. Nevertheless NOAA AR 3380 has continued to develop and isolated M-class activity is very likely, mostly from this AR, with a small chance of an X-class flare.

Coronal mass ejections

No Earth-directed Coronal Mass Ejections (CME) were observed in the last 24 hours. A partial halo CME launched yesterday 21:36 UT is judged to be back-sided.

Solar wind

The Solar Wind (SW) conditions were typical of the slow SW regime during the last 24 hours. The SW speed gradually dropped from 460 km/s to about 380 km/s in the last 24 hours. The total interplanetary magnetic field (Bt) varied between 5 and 7 nT and its North-South component (Bz) ranged between -2 and 4 nT. The interplanetary magnetic field phi angle was directed away from the Sun during the past 24 hours. The SW conditions are expected to remain in the slow SW regime in the next 24 hours.

Geomagnetism

Geomagnetic conditions were globally at quiet levels (NOAA Kp 1+ to 2) during the past 24 hours. For the same period the conditions were locally at quiet levels (K BEL 1 to 2) with the exception of the 15:00-18:00 period yesterday, when they reached unsettled conditions (K BEL 3). They are expected to remain quiet both locally and globally in the next 24 hours.

Proton flux levels

The greater than 10 MeV proton flux was at nominal levels over the past 24 hours. However, due to the increased flaring activity on the solar disk, there is a chance of a proton event in the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by the GOES-16 satellite, was at increased levels during the last 24 hours as a result of the arrival of a HSS at 26 Jul. Nevertheless, the flux remained well below the 1000 pfu alert threshold and is expected to remain below this threshold during the next 24 hours. The 24h electron fluence at nominal levels and is expected to remain so during the next 24 hours.

Today's estimated international sunspot number (ISN): 171, based on 08 stations.

Solar indices for 27 Jul 2023

Wolf number Catania	168
10cm solar flux	165
AK Chambon La Forêt	010
AK Wingst	010
Estimated Ap	008
Estimated international sunspot number	142 - Based on 14 stations

Noticeable events summary

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

All times in UTC

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