Viewing archive of Saturday, 29 July 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Jul 29 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Proton event in progress (>10 MeV)

	10cm flux	Ap
29 Jul 2023	171	012
30 Jul 2023	168	005
31 Jul 2023	165	003

Solar Active Regions and flaring

Solar flaring activity was moderate during the last 24 hours, with an M4 flare produced by NOAA Active Region (AR) 3372 (magnetic type Beta, Catania group 78) yesterday 15:58 UTC. NOAA AR 3390 (magnetic type Alpha) produced two bright C-class flares, a C7 and a C6 during the last 24 hours. The yet-unnamed AR at N14E88 produced another bright C-class flare, a C6 today at 07:34 UTC. For the next 24 hours isolated M-class flares are possible with a small chance of an X-flare.

Coronal mass ejections

A partial halo Coronal Mass Ejection (CME) was automatically detected by CACTus as launched yesterday 15:48 UTC. It is associated with an M4 flare that took place on the west solar limb and has only a small chance of directly affecting Earth's environment. However, a glancing blow from this CME is to be expected in the first half of 1 Aug. Another partial halo CME can be seen in LASCO-C2 images as launched yesterday 23:12 UTC. This is associated with a large filament eruption that took place at the NE of the solar disk. This second CME is likely to arrive on Earth at the same time as the first as it has a similar speed and was launched with only a few hours difference. Hence, the two CME are expected to be detected as one event at L1.

Solar wind

The Solar Wind (SW) conditions were typical of the slow SW regime during the last 24 hours. The SW ranged from 300 km/s to 460 km/s in the last 24 hours. The total interplanetary magnetic field (Bt) varied between 4 and 7 nT and its North-South component (Bz) ranged between -6 and 7 nT. The interplanetary magnetic field phi angle was almost exclusively 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 both globally and locally quiet to unsettled (NOAA Kp 1+ to 3- and K BEL 2 to 3) during the past 24 hours. In the next 24 hours they are expected to become quiet globally and locally with short periods of unsettled conditions locally.

Proton flux levels

The greater than 10 MeV proton flux crossed the 10 pfu threshold yesterday 23:50 UTC and the 100 pfu threshold today at 05:35 UTC. This high-flux event is associated with a Coronal Mass Ejection (CME) that can be see in LASCO/C2 images from 28 Jul 15:48 UTC onwards. The greater than 100 MeV proton flux was unaffected by the CME and has remained at nominal levels. The greater than 10 MeV proton flux is expected to remain around the 100 pfu value for the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by the GOES-16 satellite, reached but not exceeded the 1000 pfu alert threshold and is expected to remain increased but below this threshold during the next 24 hours. The 24h electron fluence was at nominal levels and is expected to remain so during the next 24 hours.

Today's estimated international sunspot number (ISN): 180, based on 15 stations.

Solar indices for 28 Jul 2023

Wolf number Catania	169
10cm solar flux	168
AK Chambon La Forêt	018
AK Wingst	010
Estimated Ap	008
Estimated international sunspot number	166 - Based on 19 stations

Noticeable events summary

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

All times in UTC

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