Viewing archive of Friday, 20 October 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Oct 20 1238 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
20 Oct 2023	127	017
21 Oct 2023	125	014
22 Oct 2023	123	015

Solar Active Regions and flaring

The solar flaring activity was at low levels. The majority of the flaring activity originated from at or beyond the west limb. The three regions on disk, Catania sunspot regions 12, 4 and 9 (NOAA AR 3465, NOAA AR 3464 and NOAA AR 3468) are all simple regions and were quiet. Catania sunspot group 18, is about to rotate over the west limb. The solar flaring activity is expected to be at low levels over the next 24 hours with C-class flares likely.

Coronal mass ejections

A partial halo Coronal Mass Ejection (CME) directed to the south-east was visible in SOHO/LASCO-C2 data from 15:00 UTC October 19. This determined to be a back-sided event and will not impact Earth. A filament eruption in the south-east quadrant began to lift off at around 18:20 UTC. This produced a narrow CME in SOHO/LASCO-C2 data to the south- east visible from 19:20 UTC but is not expected to be Earth-directed.

Coronal holes

A small, negative polarity coronal hole in the northern hemisphere continues to transit the central meridian since October 19.

Solar wind

The solar wind speed ranged between 320km/s and 430 km/s. The interplanetary magnetic field was stable around 5nT for most of the period increasing slightly to 9nT near the end of the period. Bz had a minimum value of -6 nT. The interplanetary magnetic field orientation was predominantly in the positive sector (field directed away from Sun). The solar wind speed is expected to remain slightly enhanced over the next days due to possible new high-speed stream associated with the small negative polarity coronal hole which crossed the central meridian on October 16. Additional further enhancements in the speed and magnetic field may be possible on October 20 to October 22, due to the glancing blows predicted for the CMEs from October 16, 17 and 18.

Geomagnetism

During last 24 hours the geomagnetic conditions were at quiet to unsettled levels (NOAA KP and K Bel 1-3). Geomagnetic conditions are expected to be at quiet to unsettled levels generally. Active intervals are also possible between October 20 to 22, due to the predicted CME glancing blows and high-speed stream.

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): 068, based on 05 stations.

Solar indices for 19 Oct 2023

Wolf number Catania	060
10cm solar flux	129
AK Chambon La Forêt	009
AK Wingst	008
Estimated Ap	009
Estimated international sunspot number	055 - Based on 18 stations

Noticeable events summary

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

All times in UTC

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