Viewing archive of Tuesday, 11 May 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 May 11 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
11 May 2021	076	005
12 May 2021	078	007
13 May 2021	080	017

Bulletin

Solar activity was low over the past 24 hours. NOAA AR 2822 (Catania sunspot group 93) has a Beta-gamma magnetic configuration and produced only low-Beta class flares over the past 24 hours. NOAA AR 2823 (Catania sunspot group 94) is smaller and less active producing only two low-Beta class flares in the past 24 hours. A new, yet unnumbered AR is expected to turn the disk in the coming days, hence its magnetic configuration cannot yet be accessed. Solar activity is expect to be at a low level over the next 24 hours, with one or more C-class flares possible and a very small probability of an M-class flare.

No new Earth-directed Coronal Mass Ejections (CMEs) have been detected in the available coronagraphic imagery. An Earth-bound CME was detected at 16:00 UT 9 May and is expected to arrive late on 12 May.

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 remained below the 1000 pfu alert threshold and is expected to remain below this level during the next 24 hours. The 24-hour electron fluence was at nominal levels and is expected to remain so.

The Earth is under the influence of the slow solar wind. The solar wind speed ranged between 300 and 400 km/s over the past 24 hours. The Bz component of the magnetic field fluctuated between -5 and +5 nT during 10 May and show a stable increase from 0 to +5 nT for the first half of 11 May. The interplanetary magnetic field angle fluctuated significantly but was predominantly in the negative sector (directed toward the Sun). The solar wind conditions are expected to continue to reflect a slow solar wind regime for the next 24 hours. However, an ICME is expected to reach Earth later on the 12 May and it is expected to affect the solar wind conditions.

Geomagnetic conditions were quiet to unsettled (NOAA Kp 1-2 and local K Dourbes 1-3) over the past 24 hours. Geomagnetic conditions are expected to be quiet over the next 24 hours. However, the arrival of the expected ICME late on 12 May is estimated to increase the geomagnetic conditions to moderate and possibly active levels during the second half of the 12 May.

Today's estimated international sunspot number (ISN): 030, based on 20 stations.

Solar indices for 10 May 2021

Wolf number Catania	033
10cm solar flux	077
AK Chambon La Forêt	014
AK Wingst	010
Estimated Ap	008
Estimated international sunspot number	031 - Based on 32 stations

Noticeable events summary

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

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