Viewing archive of Friday, 12 March 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Mar 12 1236 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
12 Mar 2021	076	013
13 Mar 2021	075	031
14 Mar 2021	074	031

Bulletin

The Catania group 78/90 (NOAA 2808) developed small spots in its trailing part, but produced no noticeable activity in the past 24 hours. The X-ray flux remained below B-level. The newly-named NOAA 2809 region has a simple magnetic configuration and is not expected to produce any significant X-flare activity. Only background activity is expected for the next 24 hours.

No Earth-directed Coronal Mass Ejections (CMEs) have been observed in coronagraph data.

The greater than 10 MeV proton flux was at 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 peaked over the 1000 pfu event threshold during its diurnal maximum but it is expected to be weaker today. However, beyond the next 24 hours, the electron flux is expected to increase gradually due to the expected increase in solar wind velocities. The 24h electron fluence remained at moderate levels but it is expected to be reduced in the following 24 hours.

The solar wind continued to be in slow regime and its speed declined to almost 300 km/s. At around 06:00UT the expected boundary crossing occurred (into the negative sector with the magnetic field towards the sun), while the solar speed continued to decline gradually. Leading up to and following the boundary crossing, the interplanetary magnetic field increased to over 9 nT, while the Bz has been negative for a long period and gradually dropped to -8 nT. An increase in the solar speed is expected and is estimated to reach 500 km/s gradually.

Geomagnetic conditions were quiet to unsettled (NOAA Kp: 0-3, local K Dourbes: 1-3). An increase to active conditions may occur due to the boundary crossing that took place and the enhanced solar wind conditions that are expected over the next days.

Today's estimated international sunspot number (ISN): 012, based on 18 stations.

Solar indices for 11 Mar 2021

Wolf number Catania	024
10cm solar flux	078
AK Chambon La Forêt	013
AK Wingst	003
Estimated Ap	003
Estimated international sunspot number	021 - Based on 18 stations

Noticeable events summary

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

All times in UTC

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