Prohlížíte si archiv čtvrtek 22. července 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Vydáno: 2021 Jul 22 1239 UTC

SIDC Forecast

Sluneční erupce

C-class flares expected, (probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Sluneční protony

Quiet

	10cm flux	Ap
22 Jul 2021	094	013
23 Jul 2021	092	009
24 Jul 2021	090	005

Bulletin

Solar activity was at low levels with two C-class flares recorded over the past 24 hours. There are currently six active regions on the visible disc: Catania sunspot group 17/NOAA 2842 (magnetic type beta), Catania sunspot group 20/NOAA 2845 (magnetic type beta), Catania sunspot group 22/NOAA 2846 (magnetic type beta), Catania sunspot group 20/NOAA 2847 (magnetic type beta), Catania sunspot group 21/NOAA 2848 (magnetic type alpha) and a new region Catania sunspot group 24/NOAA 2849 (magnetic type alpha), which just rotated from the south-east limb.The newly rotated Catania sunspot group 24/NOAA 2849 is responsible for a C1.2 class flare with peak time 16:04 UTC on July 21st. Catania sunspot group 20/NOAA 2845 has increased its complexity and produced a C1.3 class flare with peak time at 20:05 UTC on July 21st. The X-ray flare activity for the next 24 hours is expected to remain at low levels with 80% probability for C-class flaring.

No Earth-directed coronal mass ejections (CMEs) were detected in the available coronagraph imagery. The CME associated with the B5.4 flare from NOAA 2846 on 20 Jul has a low probability for a glancing blow on Earth in the evening of July 23rd.

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 2MeV electron flux remained under the 1000 pfu threshold and is expected to remain so. The 24h electron fluence was at nominal levels and is expected to remain in the next 24 hours.

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) remained slightly enhanced due to the high speed stream from a small positive polarity coronal hole. The solar wind speed varied between 407 and 539 km/s. The total magnetic field remained weak in the range of 3.1 to 7.7 nT. The north-south (Bz) component was in the negative sector for a long period of time, causing active geomagnetic conditions. It varied in the range of -7.4 to +2.5 nT. The interplanetary magnetic field was predominantly in the positive sector (directed away from the Sun).

The geomagnetic conditions over the past 24 hours were quiet to active. Quiet to unsettled geomagnetic conditions are expected for the next 24 hours with a remaining possibility for isolated active periods. Unsettled to active conditions could persist on July 23rd should a glancing blow from the CME from July 20th reach the Earth. Another faint and patchy coronal hole has crossed the central meridian and might result in unsettled to active conditions early on July 25th if it becomes geo-effective.

Today's estimated international sunspot number (ISN): 073, based on 25 stations.

Solar indices for 21 Jul 2021

Wolf number Catania	077
10cm solar flux	094
AK Chambon La Forêt	///
AK Wingst	010
Estimated Ap	008
Estimated international sunspot number	065 - Based on 31 stations

Noticeable events summary

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

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