Viewing archive of Thursday, 16 December 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Dec 16 1312 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
16 Dec 2021	103	010
17 Dec 2021	109	010
18 Dec 2021	107	006

Bulletin

Regions Catania 82, Catania 83/NOAA 2905, NOAA 2906,Catania 84/NOAA 2907, Catania 86/NOAA2908 and Catania 87/NOAA 2909 and an unnamed region on NE are present on the visible solar disk Region Catania 84 continue being the source of a series of C-class flares, with stronger output that of a C8.1-class, recorded by GOES on Dec 15 10:31UT. Region Catania 77/NOAA 2909 was the source of a C1.3-class flare in Dec 16 03:44UT. C class flares can be expected and M class flares possible over the next 24 hours.

The type II and IV radio emissions followed the C1.3-class flare, while a Coronal Mass Ejection ( CME) was seen at Lasco at 04:240UT. None of the observed CMEs over the past 24 hours were confirmed to be Earth-directed.

The greater than 10 MeV proton flux was at nominal levels in the past 24 hours and is expected to remain at nominal levels in the next 24 hours, depending the flaring activity. The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold and is expected to slowly start increasing but remain below this level during the next 24 hours. The greater than 2 MeV electron fluence was at nominal levels in the past 24 hours and is expected to slowly start increasing towards moderate levels.

Over the past 24 hours, the solar wind parameters (ACE+DSCOVR) showed the effects of high-speed streams (HSS) emanating from the two negative polarity Coronal Holes (CH) crossing Central Meridian (CM) Dec 12-13. The total magnetic field ranged from 3-10 nT, and its southward component, Bz, fluctuated between -8 nT and +7 nT in the past 24 hours. The solar wind speed fluctuated between 500-570 km/s. The interplanetary magnetic field phi angle has been predominantly on the negative sector (directed towards the Sun). Over the next 24 hours, we are expecting to see those effects slowly diminishing.

Geomagnetic conditions were quiet to unsettled over the past 24 hours (NOAA Kp 2-3 and K-BEL 1-3). Geomagnetic conditions are expected to be quietly to unsettled over the next 24 hours.

Today's estimated international sunspot number (ISN): 097, based on 13 stations.

Solar indices for 15 Dec 2021

Wolf number Catania	086
10cm solar flux	103
AK Chambon La Forêt	019
AK Wingst	010
Estimated Ap	010
Estimated international sunspot number	079 - Based on 15 stations

Noticeable events summary

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

All times in UTC

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