Viewing archive of Saturday, 10 July 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jul 10 1237 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
10 Jul 2021	073	011
11 Jul 2021	075	011
12 Jul 2021	076	020

Bulletin

Solar activity was at low levels. NOAA Active Region (AR) 2840, which has already rotated over the west limb, produced a C4 and B8 flare, peaking at 1725UT and 1457UT, respectively. NOAA AR 2839 (Catania sunspot group 12) was inactive decayed to a plage region. Newly numbered NOAA AR 2841 (Catania sunspot group 15) produced a series of low level B-flares. A new, as yet unnumbered, active region has rotated over the north-east limb but has not produced any significant flaring activity. A Solar activity is expected to be very low over the next 24 hours with a low probability of C-class flares.

No Earth directed Coronal Mass Ejections (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 varied between 300 and 350 km/s for most of the period, before increasing to values around 380 km/s from 0750UT. The total magnetic field had a maximum of 12 nT. The Bz varied between -9 and +8 nT, with an extended period of negative Bz between 2300UT and 0400UT. 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 July 11, 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 10 and 11 increasing to active conditions from July 12 due to the aforementioned HSS.

Today's estimated international sunspot number (ISN): 015, based on 13 stations.

Solar indices for 09 Jul 2021

Wolf number Catania	023
10cm solar flux	074
AK Chambon La Forêt	014
AK Wingst	005
Estimated Ap	005
Estimated international sunspot number	011 - Based on 29 stations

Noticeable events summary

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

All times in UTC

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