Viewing archive of Saturday, 21 October 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Oct 21 1241 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
21 Oct 2023	126	026
22 Oct 2023	124	021
23 Oct 2023	124	019

Solar Active Regions and flaring

The solar flaring activity was at low levels. Two new regions emerged over the period (NOAA 3469 and NOAA 3470). NOAA AR 3465 decayed, while NOAA AR3468 was stable. Previously number region NOAA AR 3467, re-emerged and produced most of the flaring activity including a C2.8 flare, peaking at 00:30. The solar flaring activity is expected to be at low levels over the next 24 hours with C-class flares likely.

Coronal mass ejections

No Earth directed Coronal Mass Ejections (CMEs) have been detected in the available coronagraph imagery.

Solar wind

The solar wind parameters indicated a weak transient magnetic field structure, likely one of the predicted glancing CME arrivals that were predicted. The interplanetary magnetic field was stable around 10nT for most of the period. Bz was predominantly negative and had an extended period near -9 nT from 03:00 UTC on October 21. The solar wind speed decreased gradually from 370 to near 300 km/s. The interplanetary magnetic field orientation was predominantly in the positive sector (field directed away from Sun). The interplanetary magnetic field is expected to remain slightly enhanced on October 21 and 22, due to ongoing possible CME influences. Additionally, the influence of weak high speed stream from the small negative polarity coronal holes, which crossed the central meridian on October 16 and 19, could increase the solar speed wind slightly.

Geomagnetism

During last 24 hours the geomagnetic conditions reached minor storm conditions globally and active conditions locally (NOAA KP 1-5 and K Bel 2-4). Geomagnetic conditions are expected to be at unsettled to active levels on October 21 to 23, with further minor storm intervals are also possible, due to the low probability of further CME glancing blows.

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 nominal levels. The electron fluence is expected to be at nominal levels for the next days.

Today's estimated international sunspot number (ISN): 072, based on 08 stations.

Solar indices for 20 Oct 2023

Wolf number Catania	///
10cm solar flux	126
AK Chambon La Forêt	028
AK Wingst	010
Estimated Ap	010
Estimated international sunspot number	066 - Based on 10 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page