Viewing archive of Friday, 29 December 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Dec 29 1247 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
29 Dec 2023	149	006
30 Dec 2023	150	005
31 Dec 2023	150	015

Solar Active Regions and flaring

The solar flaring activity remained at low levels. The strongest activity was marked by an impulsive C9.8 flare, peak time 07:54 UTC on Dec 29th, produced by NOAA AR 3533 (beta), which together with NOAA AR 3530 (beta) contributed to most of the flaring activity over the past 24 hours. Isolated low flaring was produced by returning active regions from behind the east limb, as well as by NOAA AR 3529 (beta) and possibly NOAA AR 3526 from behind the west limb. A new small region was numbered, NOAA AR 3535 (beta), but has remained stable and silent, as well as NOAA AR 3534 (beta) and NOAA AR 3531 (beta). The solar flaring activity is expected to be at low levels over the coming days with likely C-class flares and some chances for isolated M-class flaring.

Coronal mass ejections

A north-east partial halo coronal mass ejection (CME) is visible in the LASCO/C2 coronagraph imagery around midnight UTC on Dec 28th. The CME has no clear on disc signatures and is deemed to be back- sided with no expected impact on Earth. No Earth-directed CMEs have been detected in the available coronagraph imagery over the past 24 hours.

Coronal holes

The large negative polarity equatorial coronal hole reported in the previous ursigram has now crossed the central meridian. The high speed stream related to this coronal hole could arrive to Earth on Dec 31st or Jan 1st.

Solar wind

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) were slightly disturbed with decrease in temperature and slight increase in the density and the amplitude of the interplanetary magnetic field. These could be caused by the passage of the slow partial halo CME from Dec 25th. The solar wind velocity was steadily decreasing towards 370 km/s. The interplanetary magnetic field reached a maximum value of 9.4 nT with a minimum Bz of -6.6 nT. The B field remained almost entirely in the positive sector (directed away from the Sun). The solar wind conditions in the next 24 hours are expected to be slightly elevated due to the ongoing disturbance. Return to nominal solar wind conditions is expected on Dec 30th and further enhancements due to an anticipated high speed stream arrival are expected on Dec 31st or Jan 1st.

Geomagnetism

The geomagnetic conditions over the past 24 hours were quiet. Mostly quiet to unsettled geomagnetic conditions are expected in the next 24 hours with possible active periods and small chances of an isolated minor storm due to the ongoing ICME arrival. Mostly quiet to unsettled conditions are expected on Dec 30th and quiet to minor storm levels with possible isolated moderate storms can be foreseen with the anticipated high speed stream arrival on Dec 31st and Jan 1st.

Proton flux levels

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

Electron fluxes at geostationary orbit

The greater than 2 MeV GOES 16 electron flux was below the 1000 pfu threshold and is expected to remain so in the upcoming days.The 24h electron fluence was at nominal level and is expected to remain so in the next days.

Today's estimated international sunspot number (ISN): 086, based on 09 stations.

Solar indices for 28 Dec 2023

Wolf number Catania	///
10cm solar flux	147
AK Chambon La Forêt	007
AK Wingst	002
Estimated Ap	002
Estimated international sunspot number	097 - Based on 12 stations

Noticeable events summary

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

All times in UTC

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