Viewing archive of Sunday, 11 July 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jul 11 1234 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Quiet

	10cm flux	Ap
11 Jul 2021	075	011
12 Jul 2021	075	032
13 Jul 2021	076	014

Bulletin

Solar activity was at very low levels. NOAA Active Region (AR) 2841 (Catania sunspot group 15) produced a number of B-flares but has also begun to decay. Newly numbered NOAA AR2842, which rotated over the north- east limb yesterday, has not produced any significant flaring activity. Solar activity is expected to be very low over the next 24 hours with a low probability of C-class flares.

A possible filament eruption in the NE quadrant was observed in SDO/AIA 304 imagery from 2009UT July 10. An analysis of any possible associated Coronal Mass Ejection (CME) will be made when the coronagraph data become available. A faint partial halo CME was observed in LASCO-C2 data from 1636UT but is determined to be back-sided and therefore will not impact the Earth. No Earth directed CMEs have been detected in the available coronagraph imagery.

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 24h electron fluence was at nominal levels and is expected to remain so.

The solar wind speed became slightly enhanced over the period, with values gradually increasing to 450 km/s before falling again from 00UT to around 350 km/s by the end of the period. The total magnetic field had a maximum of 8 nT. The Bz varied between -5 and +6 nT. The interplanetary magnetic field phi angle was predominantly in the positive sector (directed away from the Sun). The solar wind speed and magnetic field are expected to become enhanced from late early on July 12, due to the arrival of the High Speed Stream (HSS) associated with the with the patchy negative polarity Coronal Hole (CH) that began to cross the central meridian on July 09.

Geomagnetic conditions were quiet to unsettled (NOAA Kp and local K Dourbes 0-3) over the past 24 hours. Geomagnetic conditions are expected to be quiet to unsettled on July 11 increasing to active conditions from July 12, with minor storm conditions possible due to the arrival of the aforementioned HSS.

Today's estimated international sunspot number (ISN): 020, based on 18 stations.

Solar indices for 10 Jul 2021

Wolf number Catania	///
10cm solar flux	074
AK Chambon La Forêt	008
AK Wingst	008
Estimated Ap	008
Estimated international sunspot number	017 - Based on 17 stations

Noticeable events summary

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

All times in UTC

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