Viewing archive of Thursday, 12 September 2024

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2024 Sep 12 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Quiet

	10cm flux	Ap
12 Sep 2024	207	032
13 Sep 2024	211	024
14 Sep 2024	212	012

Solar Active Regions and flaring

Solar flaring activity was high during the past 24 hours, with an X1.3 and nine M-class flares registered in total. A yet-unnamed Active Region (AR) at S14E85 produced the X-class flare at 12 Sep 09:43 UTC and an M-1.9 at 11 Sep 15:30 UTC. NOAA AR 3811 (magnetic configuration Beta, Catania sunspot group no 89) produced five M-class flares, with the brightest being an M5.0 at 12 Sep 00:12 UTC. NOAA AR 3814 produced three M-class flares, with the brightest being an M2.0 at 11 Sep 17:52. As the AR at S14E85 is too close to the solar limb for an accurate assess of its magnetic complexity, it is difficult to estimate the chances for another X-class flare in the next 24 hours. In any case, numerous M-class flares are very likely to take place during the next 24 hours.

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 arrivals first of a glancing blow associated with the Coronal Mass Ejection (CME) of the 9 Sep and then the arrival of the CME of 10 Sep. Starting from 11 Sep 14:30 UTC, the SW speed increased from 330 km/s to almost 400 km/s, while the total interplanetary magnetic field (Bt) increased from 2 nT to 10 nT. The North-South component of the magnetic field (Bz) varied between -5 and 8 nT during the glancing blow. The CME of 10 Sep became geo-effective at 12 Sep 03:00 UTC and caused a rapid increase of the SW speed to 570 km/s. The total interplanetary magnetic field (Bt) increased from 27 nT and its North-South component varied between -21 nT and 16 nT. The interplanetary magnetic field phi angle varied a lot since the arrival of the CME but it was mostly directed away from the Sun during the past 24 hours. The effects of the CME arrival are expected to last for at least the next 24 hours.

Geomagnetism

Geomagnetic conditions reached globally moderate storm (Kp 6- between at 12 Sep 09:00-12:00 UTC) and minor storm levels (Kp 5+ at 12 Sep 06:00-09:00 UTC) as the result of a Coronal Mass Ejection (CME) arrival at 12 Sep 03:00 UTC. Locally the situation was milder, with K BEL at minor storm level (5) at 12 Sep 06:00-09:00 UTC and then dropping to active conditions (K BEL 4) at 09:00-12:00 UTC. Globally storm conditions (either at minor or moderate storm levels) are expected to prevail during the next 24 hours, although there is a chance of a major storm (Kp 7). Locally the conditions are also expected to remain at storm levels, albeit they are expected to be lower than the global values.

Proton flux levels

The greater than 10 MeV proton flux, as reported by GOES-18, was below the 10 pfu alert threshold level during the last 24 hours. Nevertheless, there is a chance that a proton event might occur as a result of the increased solar flaring activity.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by the GOES-18 satellite, was at nominal levels during the last 24 hours and is expected to remain at these levels during the next 24 hours. The 24h electron fluence was at very low levels during the past 24 hours and is expected to remain at these levels for the following 24 hours.

Today's estimated international sunspot number (ISN): 142, based on 11 stations.

Solar indices for 11 Sep 2024

Wolf number Catania	218
10cm solar flux	207
AK Chambon La Forêt	023
AK Wingst	012
Estimated Ap	011
Estimated international sunspot number	153 - Based on 25 stations

Noticeable events summary

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

All times in UTC

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