Viewing archive of Friday, 27 October 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Oct 27 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
27 Oct 2023	125	018
28 Oct 2023	127	013
29 Oct 2023	127	013

Solar Active Regions and flaring

Solar flaring activity increased to moderate levels in the past 24 hours. The largest flare was a long duration M1.4 flare, peaking at 23:24 on Oct 26. The flare was also associated with a Type II radio burst and originated from the region near N20E88. There are currently four numbered active regions on the solar disk. The newly numbered NOAA AR 3273 (beta class), that recently rotated into view over the east limb, produced most of the flaring activity in the last 24 hours together with NOAA AR 3471 (beta 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 level over the next 24 hours with C-class flares likely.

Coronal mass ejections

A partial halo CME was observed at 23:14 UTC (as detected by Cactus tool) on Oct 26. It is associated with a GOES M1.4 flare and a Type II radio burst. The CME is not expected to be Earth directed given the source location. No other Earth-directed Coronal Mass Ejections have been detected in the last 24 hours in the available SOHO/LASCO images.

Coronal holes

Two positive polarity coronal holes, one equatorial and one in northern hemisphere, began to transit the central meridian today, Oct 27. An associated high speed stream in in-situ solar wind measurements is expected from late on Oct 29.

Solar wind

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) reflected the ongoing influence of the high-speed stream. The solar wind speed increased to values around 560 km/s by around 21:00 UTC on Oct 26, before gradually decreasing to values around 420 km/s. The total interplanetary magnetic field had a maximum value of 11 nT going to 5 nT by the end of the period. The southward component of the interplanetary magnetic field ranged between -8 nT and 9 nT. The magnetic field orientation was predominantly in the positive sector (field directed away from the Sun). The solar wind speed is expected to continue to gradually decrease over the next days. From late on Oct 29 solar wind parameters might become slightly elevated due to the arrival of a high-speed stream from positive polarity coronal holes, that started to transit the central meridian today, on Oct 27.

Geomagnetism

During the last 24 hours the geomagnetic conditions reached minor storm conditions globally and active conditions locally (NOAA KP: 3 to 5- and K Bel 2-4). Geomagnetic conditions are expected to be at quiet to unsettled levels during the next 24 hours with a chance for isolated active and minor storm periods due to HSS influence.

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 days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux remained below the 1000 pfu threshold as measured by GOES 16. It is expected to remain below this threshold over the next days. The 24 hour electron fluence was at normal levels and is expected to remain so.

Today's estimated international sunspot number (ISN): 064, based on 08 stations.

Solar indices for 26 Oct 2023

Wolf number Catania	///
10cm solar flux	126
AK Chambon La Forêt	038
AK Wingst	024
Estimated Ap	026
Estimated international sunspot number	054 - Based on 21 stations

Noticeable events summary

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

All times in UTC

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