Viewing archive of Friday, 18 June 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jun 18 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
18 Jun 2021	074	010
19 Jun 2021	074	004
20 Jun 2021	073	004

Bulletin

Solar activity remained at very low levels in the last 24 hours. The only active region on the visible solar disc, NOAA AR2833 (Catania sunspot group 7), remains with a simple unipolar magnetic filed configuration and is now rotated towards the central meridian. The X-ray flare activity is expected to remain at very low levels for the next 24 hours.

No Earth-directed coronal mass ejections (CMEs) were detected in the available coronagraph 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 2MeV electron flux was predominantly above the 1000 pfu threshold and is expected to intermittently cross the threshold over the next 24 hours. The 24h electron fluence was at moderate levels and is expected to remain at moderate levels for the next 24 hours and return to nominal levels after.

Over the past 24h the solar wind (ACE and DSCOVR) remained under the influence of a waning high speed stream (HSS). The solar wind speed smoothly varied between 472 km/s and 556 km/s. The total magnetic field was low in the range of 2.7 nT to 5.5 nT. The Bz component also remained weak with values between -4.7 nT and 3.5 nT. The solar temperature remained elevated and the orientation of the interplanetary magnetic field remained in the negative sector, reflecting the polarity of the geo-effective coronal hole.

The geomagnetic conditions over the past 24 hours were quiet to unsettled. mostly quiet to unsettled geomagnetic conditions are expected for the next 24 hours. Isolated active periods are unlikely, but remain possible until the effects of the HSS fully fade away.

Today's estimated international sunspot number (ISN): 019, based on 18 stations.

Solar indices for 17 Jun 2021

Wolf number Catania	///
10cm solar flux	075
AK Chambon La Forêt	014
AK Wingst	006
Estimated Ap	007
Estimated international sunspot number	012 - Based on 31 stations

Noticeable events summary

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

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