Viewing archive of Friday, 15 September 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Sep 15 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
15 Sep 2023	149	013
16 Sep 2023	149	018
17 Sep 2023	147	015

Solar Active Regions and flaring

The solar flaring activity was at moderate levels, with two M-class flares and several C-class flares recorded in the past 24 hours. The largest flares of the period were an M1.9 flare, peaking at 19:31 UTC on Sept 14 and an M2.5 flare, peaking at 21:26 on Sept 15, associated with NOAA AR 3429 (beta class). This region, that has slightly simplified, was the main driver of the flaring activity observed over the past 24 hours. Isolated C-class flaring was also produced by NOAA AR 3423 (beta class), NOAA AR 3425 (beta class) and by NOAA AR 3433 (alpha class). Other regions on the disc have simple configuration of their photospheric magnetic field (alpha and beta) and did not show any significant flaring activity. The solar flaring activity is expected to be at low to moderate levels over the next 24 hours with C-class flares likely and M-class flares possible.

Coronal mass ejections

A Coronal Mass Ejection (CME) was first observed in SOHO/LASCO-C2 coronagraph data from 07:30 UTC on Sept 14th. The CME is associated with a GOES M1.4 flare and a filament eruption, that occurred in the northwestern quadrant of the Sun from around 06:26 UTC on September 14th. The CME is directed to the north-west and is estimated to give a glancing blow to Earth's environment either late on Sept 16 or early on Sept 17. No other Earth-directed CMEs have been detected in the available coronagraph imagery.

Coronal holes

A positive polarity coronal hole in the southern hemisphere has reached the central meridian today.

Solar wind

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) were slightly elevated. The solar wind speed values ranged between 430 km/s and 520 km/s. The total interplanetary magnetic decreased from 11 nT to the values around 6 nT. The southward component of the interplanetary magnetic field fluctuated between -10 nT and 7 nT. The magnetic field orientation was predominantly in the negative sector (field directed towards the Sun). The solar wind parameters are expected to be slightly elevated during the next days due to the high-speed stream influence, with a further enhancement possible on Sept 16 – Sept 17 due to the predicted arrival of CME from Sept 14.

Geomagnetism

The geomagnetic conditions over the past 24 hours were mostly quiet to unsettled (NOAA-Kp=1-3) with a single active period registered globally (NOAA-Kp=4) during the interval 18-00 UTC on Sept 14. Locally a minor storm period (K-Bel=5) was observed over Belgium between 21-00 UTC on Sept 14. Geomagnetic conditions are expected to be at quiet to unsettled levels, with a chance of increasing to active conditions and isolated minor storm periods from late on Sept 16 - early on Sept 17, due to a possible arrival of the CME from Sept 14.

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux was at nominal levels and is expected to remain so over the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by the GOES-16 satellite, was below the 1000 pfu threshold and is expected to remain below this threshold for the next days.The 24h electron fluence was at normal level. The electron fluence is expected to be at normal levels in the next days.

Today's estimated international sunspot number (ISN): 123, based on 17 stations.

Solar indices for 14 Sep 2023

Wolf number Catania	145
10cm solar flux	145
AK Chambon La Forêt	023
AK Wingst	023
Estimated Ap	022
Estimated international sunspot number	143 - Based on 26 stations

Noticeable events summary

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

All times in UTC

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