Viewing archive of Wednesday, 16 June 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jun 16 1231 UTC

SIDC Forecast

Valid from 1230 UTC, 16 Jun 2021 until 18 Jun 2021
Solar flares

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

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

10cm fluxAp
16 Jun 2021073021
17 Jun 2021073008
18 Jun 2021072005

Bulletin

Solar activity was at very low levels with no significant flares detected in the last 24 hours. NOAA AR2833 (Catania sunspot group 7) remained inactive with a simple unipolar magnetic field configuration. No other regions are visible on the solar disc. 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 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 predominantly at nominal levels in the next 24 hours. Intermittent transitions to moderate levels are possible.

Over the past 24h the solar wind parameters (ACE and DSCOVR) were elevated due to the arrival of a CIR around 12 UTC on June 15th followed by a high speed stream (HSS). Between 12 UTC and 14 UTC on June 15th the solar wind speed showed a rapid increase from below 400 km/s to approximately 600 km/s and remained about 580 km/s on average after. The total magnetic field varied between 3 nT and 16 nT. The Bz component fluctuated mildly with typical values above - 5nT with the exception of a short-lived minimum of -14 nT registered at the arrival of the CIR. The solar wind temperature was elevated as expected for HSS conditions and the orientation of the interplanetary magnetic field was predominantly in the negative sector, reflecting the polarity of the geo-effective coronal hole. The solar wind parameters are expected to remain elevated over the day and slowly return to background slow solar wind conditions on June 18th as the effect of the HSS subsides.

The geomagnetic conditions over the past 24 hours were unsettled to active with an isolated period of minor storm conditions as registered by the Kp index between 18:00 and 21:00 UTC on June 15th. Locally, in Dourbes, the observed geomagnetic conditions were quiet to active. Unsettled to active geomagnetic conditions are expected for the next 24 hours with chances for an isolated minor geomagnetic storm due to the ongoing HSS.

Today's estimated international sunspot number (ISN): 011, based on 22 stations.

Solar indices for 15 Jun 2021

Wolf number Catania012
10cm solar flux076
AK Chambon La Forêt031
AK Wingst022
Estimated Ap021
Estimated international sunspot number011 - Based on 34 stations

Noticeable events summary

DayBeginMaxEndLocStrengthOP10cmCatania/NOAARadio burst types
None

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

All times in UTC

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