Viewing archive of Wednesday, 1 December 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Dec 01 1234 UTC

SIDC Forecast

Solar flares

Quiet conditions (<50% probability of C-class flares)

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
01 Dec 2021	090	011
02 Dec 2021	088	020
03 Dec 2021	086	009

Bulletin

Solar activity was at very low levels over the last 24 hours. There were five Active Regions (AR) visible on the Sun over the past 24 hours. NOAA AR 2901 and 2903 have decayed into plage regions. The three remaining active regions have also been stable and not produced any significant activity. Solar activity is expected to be at very low levels, with a chance for a C-class flare.

No Earth directed CMEs have been detected in the available coronagraph imagery.

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 was below the 1000 pfu alert threshold in the past 24 hours and is expected to remain so in the next 24 hours. The greater than 2 MeV electron fluence was at nominal levels in the past 24 hours, and is expected to stay at nominal levels in the next 24 hours.

The solar wind data reflected the arrival of a high speed stream that was stronger than expected, likely associated with the patchy positive polarity coronal hole in the northern hemisphere, which began to cross the central meridian on Nov 28. The solar wind speed (DSCOVR) began to increase from 19UT Nov 30, reaching values of around 580 km/s before reducing slightly. The total magnetic field increased to 15 nT at this time, with an extended period of negative Bz between 19UT and 23UT. The interplanetary magnetic field phi angle was predominantly in the positive sector (directed away from the Sun). The solar wind speed is expected to remain elevated over the coming days in response to this High Speed Stream (HSS) and another HSS expected from another positive polarity Coronal Hole (CH) that began to traverse the central meridian on Nov 30.

Geomagnetic conditions were at quiet levels for the first half of the period, increasing to active and minor storm level conditions due to the HSS arrival and the extended period on negative Bz (NOAA Kp and K-BEL recorded values of 1-4 and 1-5, respectively). Geomagnetic conditions are expected to be unsettled to active on Dec 01, with minor storm conditions possible on Dec 02 due to the arrival of the next expected HSS.

Today's estimated international sunspot number (ISN): 038, based on 10 stations.

Solar indices for 30 Nov 2021

Wolf number Catania	068
10cm solar flux	090
AK Chambon La Forêt	033
AK Wingst	014
Estimated Ap	014
Estimated international sunspot number	060 - Based on 20 stations

Noticeable events summary

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

All times in UTC

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