Viewing archive of Friday, 16 July 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jul 16 1230 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
16 Jul 2021	077	003
17 Jul 2021	076	002
18 Jul 2021	075	001

Bulletin

Solar activity was at low levels in the past 24 hours, with two C1-class flares detected. NOAA Active Region (AR) 2843 (Catania group 18) produced both flares on 16 July at 07:27UT and 08:37UT. NOAA AR 2842 (Catania group 17) continued to decay and did not produced any notable flare activity. NOAA AR 2843 might produce more C-type activity in the next 24 hours. An AR turning into Earth view has been active and produced a number of CMEs during the last 24 hours, hence there is a likelihood that flare activity might be detected originating from this area.

A filament eruption in the NE quadrant was observed in SDO/AIA 304 imagery from 20:00UT July 15. An analysis of any possible associated Coronal Mass Ejection (CME) will be made when the coronagraph data become available. Several CMEs were detected in the past 24 hours, including a bright halo CME, however none of them appears Earth-directed.

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 390 and 490 km/s during the last 24 hours. The total magnetic field dropped from 9 nT to 1 nT in the last 24 hours. The Bz varied between -6 and 7 nT during the first part of the last 24 hours and then gradually reach values close to zero. The interplanetary magnetic field phi angle was predominantly in the negative sector (directed towards the Sun) during the last 24 hours. The solar wind conditions are expected to remain to a slow solar wind regime for the next 24 hours.

Geomagnetic conditions were quiet to moderate globally (NOAA Kp index 1-3) and quiet locally (K Dourbes 1-2) over the past 24 hours. As the solar wind has now a typical slow regime, geomagnetic conditions are expected to be quiet in the next 24 hours.

Today's estimated international sunspot number (ISN): 032, based on 16 stations.

Solar indices for 15 Jul 2021

Wolf number Catania	023
10cm solar flux	074
AK Chambon La Forêt	015
AK Wingst	014
Estimated Ap	013
Estimated international sunspot number	017 - Based on 22 stations

Noticeable events summary

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

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