Viewing archive of Tuesday, 23 March 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Mar 23 1231 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
23 Mar 2021	080	008
24 Mar 2021	082	011
25 Mar 2021	082	007

Bulletin

Solar activity was at very low levels in the past 24 hours. NOAA AR 2811 and Catania group 81 produced only minor B-class flares. A new small active region rotated into view. Solar activity is expected to remain at very low levels, with a small chance of a C-class flare.

A Corona Mass Ejection (CME) was observed on 22 March, 01:10 UT. It has an Earth-directed component and its speed is estimated to 250-300 km/s. It is expected to reach Earth on 26 March.

The greater than 10 MeV proton flux was below nominal levels over the past 24 hours and is expected to remain so for the next 24 hours. The greater than 2 MeV electron flux exceeded the 1000 pfu threshold in the past 24 hours and is expected to remain elevated in the next 24 hours. The 24h electron fluence was at moderate levels in the last 24 hours and is expected to remain at moderate levels in the next 24 hours.

Solar wind conditions reflected a fading fast solar stream over the last 24 hours. The solar wind speed decreased from 580 km/s to 510 km/s. The interplanetary magnetic field magnitude was around 4 nT. Bz was between 2 and -3 nT. The magnetic field phi angle was predominantly in the negative sector (directed towards the Sun). The solar wind speed is expected to decrease further in the next 24 hours.

Geomagnetic conditions reached active levels in Kp (with values between 2 and 4) and local K Dourbes varied between 1 and 3 over the past 24 hours. The CME observed on 20 March is expected to arrive within 24 hours and cause at most active conditions (otherwise mostly quiet conditions expected).

Today's estimated international sunspot number (ISN): 024, based on 14 stations.

Solar indices for 22 Mar 2021

Wolf number Catania	///
10cm solar flux	080
AK Chambon La Forêt	014
AK Wingst	008
Estimated Ap	008
Estimated international sunspot number	022 - Based on 24 stations

Noticeable events summary

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

All times in UTC

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