Viewing archive of Thursday, 21 December 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Dec 21 1256 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
21 Dec 2023	205	006
22 Dec 2023	205	018
23 Dec 2023	204	022

Solar Active Regions and flaring

The solar flaring activity was at moderate level during the last 24 hours, with several C-class flares and a M-class flare. The strongest flare was GOES M4.2 flare from NOAA AR 3519 which peaked at 05:38 UTC on Dec 21. During the flare, the source region (AR 3519) of the flare had beta configuration of its photospheric magnetic field. The solar flaring activity is expected to be at low to moderate levels over the next 24 hours with few C-class flares, possibly M-class flares and a low chance for isolated X-class flares.

Coronal mass ejections

No Earth-directed coronal mass ejections (CMEs) were detected in the available coronagraph observations during last 24 hour.

Coronal holes

A negative polarity coronal hole crossed the central meridian on Dec 20 and a high-speed stream from this coronal hole may arrive to Earth from December 22.

Solar wind

Solar wind conditions have transitioned from fast to slow solar wind. The solar wind speed ranged between 350 km/s and 490 km/s. The North- South component (Bz) ranged between -4 and 3 nT. The interplanetary magnetic field ranged from 1 nT to 5 nT. Slow solar wind conditions are expected to continue over the next 24 hours unless the high speed streams from the negative polarity coronal hole, which started to cross the central meridian on Dec 18, impact the Earth.

Geomagnetism

Geomagnetic conditions were globally and locally at quiet to unsettled conditions (NOAA Kp and K BEL 1 to 3) over the past 24 hours. It is expected to remain so unless the high speed streams from the negative polarity coronal hole, which started to cross the central meridian on Dec 18, impact the Earth.

Proton flux levels

The greater than 10 MeV proton flux was below the threshold level over the past 24 hours and is expected to remain so for the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by the GOES-16 satellite, was just below the threshold level in the last 24 hours. It increased probably due to enhanced solar wind conditions but remained just below the 1000 pfu alert threshold level. It may increase even further and cross the threshold during the next 24 hours. The 24h electron fluence was at normal level and is expected to remain so.

Today's estimated international sunspot number (ISN): 147, based on 03 stations.

Solar indices for 20 Dec 2023

Wolf number Catania	231
10cm solar flux	195
AK Chambon La Forêt	014
AK Wingst	011
Estimated Ap	012
Estimated international sunspot number	160 - Based on 14 stations

Noticeable events summary

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

All times in UTC

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