Viewing archive of Monday, 17 July 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Jul 17 1234 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

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

Solar protons

Proton event expected (10 pfu at >10 MeV)

	10cm flux	Ap
17 Jul 2023	184	023
18 Jul 2023	180	018
19 Jul 2023	176	010

Solar Active Regions and flaring

There are currently 5 numbered active regions on the visible disk. Solar flaring activity over the past 24 hours remained at moderate levels with an M4.0-flare, peak time 17:46 UTC on July 16, which was produced by NOAA AR 3363 and another impulsive M1.8-flare associated with a type II-radio burst, peak time 15:08 UTC, on July 16, which was produced by NOAA AR 3372. Both NOAA AR 3363 and NOAA AR 3372 remain the two largest and most complex active regions on the visible solar disc. Another notable active region NOAA AR 3373 has produced several C-class flares, the largest being a C6.2-flare with peak time 19:14 UTC. The remaining active regions were quiet and stable. A new, as yet unnumbered active region has started to rotate onto the disk in the Northern hemisphere. The solar flaring activity is likely to remain at moderate levels over the coming days with low chance for isolated X-class flaring.

Coronal mass ejections

Two halo coronal mass ejections (CMEs) were observed in LASCO/C2 coronagraph data at 13:48 UTC on July 16 and 01:54 UTC on July 17, respectively. Both of these are deemed to be back-sided with no expected impact at Earth. No other Earth-directed CMEs have been detected in the available coronagraph imagery.

Solar wind

A fast forward shock was observed in the solar wind parameters at 18:35 UTC on July 16. The solar wind velocity increased from 376 km/s to 434 km/s. The interplanetary magnetic field jumped from 7 nT to 13 nT. The solar wind speed reached a maximum of around 500 km/s before then oscillating around 440 km/s. The magnetic field reached a peak value of 15 nT with a minimum negative Bz of -12nT. It is not clear which of the events from the past days may be responsible for this shock arrival, but it may be associated to the CME observed on July 15. Further enhancements continue to be possible from further expected ICME arrivals and possible weak high speed stream.

Geomagnetism

The geomagnetic conditions over the past 24 hours reached minor storm levels globally (NOAA KP =5 minus, K-Bel =4) around 00:00 UTC July 17. Mostly unsettle to active geomagnetic conditions with isolated minor storm periods are expected over the next two days due to the predicted weak high speed stream and further glancing blow arrivals on July 18.

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux levels were still slightly elevated but have remained below threshold levels. Further enhancements remain possible over the next days with the enhanced solar eruptive activity.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux as measured by GOES 16 and GOES 18 have remained below the 1000 pfu threshold. The greater than 2 MeV electron flux is expected to be below the 1000 pfu threshold in the upcoming days. The 24h electron fluence was at nominal levels and is expected to remain so over the next days.

Today's estimated international sunspot number (ISN): 159, based on 20 stations.

Solar indices for 16 Jul 2023

Wolf number Catania	///
10cm solar flux	184
AK Chambon La Forêt	018
AK Wingst	011
Estimated Ap	010
Estimated international sunspot number	161 - Based on 25 stations

Noticeable events summary

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

All times in UTC

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