Viewing archive of Tuesday, 17 August 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Aug 17 1231 UTC

SIDC Forecast

Valid from 1230 UTC, 17 Aug 2021 until 19 Aug 2021
Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

10cm fluxAp
17 Aug 2021075007
18 Aug 2021075007
19 Aug 2021077007

Bulletin

Solar flaring activity was at low levels. One active region is visible on the solar disk: NOAA 2857 (beta magnetic field configuration, located on the northwest quadrant), this region has grown in the last 24 hours, C-class flares are possible.

No Earth directed Coronal Mass Ejections (CMEs) were observed in the available coronagraphic imagery.

The greater than 10 MeV proton flux was at background levels in the past 24 hours, and is expected to remain so in the next 24 hours. The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold, while the 24h electron fluence was at normal levels over the past 24 hours. Over the next 24 hours they are expected to remain at those levels.

Over the past 24 hours the solar wind speed has been around 470 km/s. The total magnetic field strength was around 4 nT, with positive polarity (directed away from the Sun). Same conditions are expected for the next 24 hours.

Geomagnetic conditions were at quiet to unsettled levels (NOAA Kp 1-2 and K Dourbes 0-3) over the past 24 hours. Similar conditions are expected over the next 24 hours.

Today's estimated international sunspot number (ISN): 013, based on 10 stations.

Solar indices for 16 Aug 2021

Wolf number Catania018
10cm solar flux074
AK Chambon La Forêt009
AK Wingst012
Estimated Ap010
Estimated international sunspot number017 - Based on 27 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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The strength of the interplanetary magnetic field is moderate (11.52nT), the direction is North (0.35nT).
A southern hemisphere coronal hole was detected in an earth-facing position on Tuesday, 8 April 2025

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