Viewing archive of Saturday, 20 August 2022

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2022 Aug 20 1237 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Quiet

	10cm flux	Ap
20 Aug 2022	099	021
21 Aug 2022	097	026
22 Aug 2022	093	017

Bulletin

Solar flaring activity was at low levels. The largest flare was a C6.7 flare, associated with NOAA AR 3078, peaking on August 19 at 20:31 UT. The flare was also associated with a Type II radio signature. NOAA AR 3078 has begun to gradually decay. NOAA AR3081 was stable and produced low level C-class flaring, The two remaining regions, NOAA AR 3082 and 3084, both decayed and were quiet. Solar flaring activity is expected to be at low levels, with C-class flares likely, and a remaining chance for M-class flares.

The two Coronal Mass Ejections mentioned yesterday have been analysed. The first CME, first seen in LASCO C2 at 23:00 UT August 18 to the south west, is not deemed to be Earth directed. The second CME, first visible in LASCO C2 at 04:49UT August 19, is also mostly directed to the south-west. However, in LASCO C3 a faint partial halo signature can also be seen. A glancing blow at Earth may be expected on August 22. No other Earth directed CMEs have been observed in the 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 days. The greater than 2 MeV electron flux was crossed the 1000 pfu threshold. It is expected to be again around the threshold in the next 24 hours. The 24h electron fluence was at nominal to moderate levels and is expected to be at nominal to moderate levels in the next 24 hours.

At the start of the period, the solar wind speed was enhanced with values around 560 km/s. A small shock was observed in the solar wind speed and magnetic field on 19 August 17:03UT. The value of the total magnetic field increased from 8 to 12nT, the solar wind speed from 562 to 640 km/s. Bz had a minimum value of -11nT. After the shock arrival, the solar wind speed reached a maximum of 684 km/s before beginning to decrease gradually to values near 500 km/s. The magnetic field strength also began to decrease and by the end of the period was around 5nT. The magnetic field orientation was mostly in the negative sector (field directed towards the Sun). The solar wind speed and magnetic field are expected to remain enhanced over the next 24 hours, due to the continued combination of effects from the high-speed stream and possible another ICME glancing blow predicted for early on August 21 from the CME observed on August 18.

Geomagnetic conditions were at quiet to unsettle levels at the start of the period before increasing to active conditions, with an isolated period of minor storm conditions recorded globally (NOAA Kp=5) between 18:00 and 00:00 UT. This was in response to the shock arrival and enhanced solar wind speed. The conditions returned to quiet to unsettled levels from 04:00 UT August 20. Geomagnetic conditions for the next 24 hours are expected to be mostly at unsettled to active levels. Due to the possible arrival of another ICME on August 21 and in combination with the current high-speed stream, further intervals of minor storm conditions are also possible.

Today's estimated international sunspot number (ISN): 088, based on 17 stations.

Solar indices for 19 Aug 2022

Wolf number Catania	///
10cm solar flux	105
AK Chambon La Forêt	032
AK Wingst	021
Estimated Ap	022
Estimated international sunspot number	097 - Based on 23 stations

Noticeable events summary

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

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