Viewing archive of Thursday, 25 February 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Feb 25 1258 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
25 Feb 2021	081	014
26 Feb 2021	078	007
27 Feb 2021	078	006

Bulletin

The solar activity has been mostly quiet over the past 24 hours. Regions Catania 74/NOAA AR 2804 and Catania 75/NOAA 12805 had a low flaring activity. The solar flaring activity is expected to remain at low levels for the next 24 hours.

No Earth directed Coronal Mass Ejections (CME) were observed in the available coronagraphic imagery.

The greater than 10 MeV proton flux was at nominal levels in the past 24 hours and is expected to remain so in the next 24 hours. The greater than 2 MeV electron flux remained over the 1000 pfu threshold for the second half of Feb 24. It is expected to have values around the threshold for the next 24 hours, as a response to the possible arrival on Feb 24 of the CME that took place on Feb 20. The greater than 2 MeV electron fluence remained on moderate levels in the past 24 hours. It is expect to be at moderate levels for the next 24 hours.

The past 24 hours the solar wind speed ranged between 430 km/s and 510 km/s. The total magnetic field ranged between 3 nT and 10 nT. The Bz component fluctuated between -8 nT and 8 nT. The orientation of the Interplanetary Magnetic Field (IMF) fluctuated from the negative (towards the Sun) to the positive sector (away from the Sun). The solar wind parameters reflect the effects of a possible glancing blow of the sides of the CME from Feb 20. An extension of the northern positive Coronal Hole (CH) is expected to cross the Central Meridian (CM) tomorrow. The same applies for the negative polarity southern CH crossing the solar disc. The associated high speed streams should be expected about Feb 29 and not Feb 26 as was previously erroneously reported.

The geomagnetic conditions over the past 24 hours were active (K Dourbes and Kp=4), as a possible response to the CME glancing blow. They are expected to return to mainly quiet to unsettled levels for the next 24 hours, with a slight chance of an isolated active event (K Dourbes=4).

Today's estimated international sunspot number (ISN): 033, based on 21 stations.

Solar indices for 24 Feb 2021

Wolf number Catania	043
10cm solar flux	081
AK Chambon La Forêt	039
AK Wingst	///
Estimated Ap	015
Estimated international sunspot number	034 - Based on 22 stations

Noticeable events summary

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

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