Viewing archive of Sunday, 19 December 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Dec 19 1254 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
19 Dec 2021	121	005
20 Dec 2021	125	006
21 Dec 2021	127	010

Bulletin

Over the past 24 hours, four new regions have appeared on the southern hemisphere and one on the northern. One of the new regions produced the flare of the largest X-ray output over that time, a C6.3-class flare with estimated location S19E89 and occurring on Dec 18 17:27UT. C-class flares can be expected and M-class flares are possible over the next 24 hours.

The C6.3 class flare seemed to be followed by a coronal mass ejection detected by Cactus on Lasco data on Dec 18 18:12UT, with a projected speed of 536 km/s. No Stereo data from that time are available current;y , but due to its location, any possible influence is unlikely and minimal.

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. The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold and is expected to remain nuder the threshold during the next 24 hours. The greater than 2 MeV electron fluence was at nominal levels in the past 24 hours where it is expected to remain.

Over the past 24 hours, the total magnetic field had values between 1 and 9nT, and its southward component, Bz, fluctuated between -4 nT and +5 nT. The solar wind speed ranged from 320 to 390 km/s. The interplanetary magnetic field phi angle was predominantly on the negative sector (directed towards the Sun). Over the next 24 hours, we are expecting the mild influence of the high speed stream emanating from the small negative polarity coronal hole at the SW quadrant.

Geomagnetic conditions were quiet over the past 24 hours (NOAA Kp and K-BEL 0-2). Geomagnetic conditions are expected to be quiet to unsettled over the next 24 hours.

Today's estimated international sunspot number (ISN): 115, based on 13 stations.

Solar indices for 18 Dec 2021

Wolf number Catania	///
10cm solar flux	121
AK Chambon La Forêt	007
AK Wingst	004
Estimated Ap	003
Estimated international sunspot number	099 - Based on 09 stations

Noticeable events summary

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

All times in UTC

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