Viewing archive of Tuesday, 4 July 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Jul 04 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
04 Jul 2023	172	009
05 Jul 2023	174	011
06 Jul 2023	172	009

Solar Active Regions and flaring

The solar flaring activity was at low level with several C-class flares being detected in the last 24 hours. The largest flare was a C8.9 flare, peaking at 21:12 UTC on July 03, associated with NOAA AR 3360 (alpha class). NOAA AR 3354 (beta-gamma-delta class) remains the largest and most complex active region on the disk but produced only low C-class flares. Several C-class flares were also produced by NOAA AR 3358 (beta class) and by NOAA AR 3359 (beta class). The solar flaring activity is expected to be at low to moderate levels over the next 24 hours with a chance for isolated X-class flare.

Coronal mass ejections

In the past 24 hours, several coronal mass ejections (CME) and flows were observed in the available SOHO/LASCO coronagraph imagery and automatically detected by the Cactus tool over. In particular, the CME was observed in SOHO/LASCO-C2 at around 21:48 UTC on July 03, likely related to the C8.9 flare from NOAA AR 3360 with an accompanying type II radio burst detected at around 21:31 UTC. The CME is directed to the east and the bulk of the CME is not expected to be Earth directed. However, a glancing blow at Earth may be possible. Full analysis is still ongoing, and more details will be provided later. Another CME, directed to south-east, was observed in SOHO/LASCO-C2 at around 04:12 UTC on July 04 with an associated on-disc dimming. We are awaiting corresponding coronagraph data for further analysis. No other Earth- directed CMEs have been detected in the available coronagraph imagery.

Coronal holes

A large positive polarity coronal hole began to transit the central meridian on July 04. An associated high speed stream in in-situ solar wind measurements is expected for July 07.

Solar wind

Over the past 24 hours the solar wind parameters were reflecting slow solar wind conditions. The solar wind speed was below 400 km/s. The interplanetary magnetic field magnitude ranged between 5 - 7 nT. The southward component of the interplanetary magnetic field fluctuated between -3 nT and 4 nT. The magnetic field orientation was predominantly in the positive sector (field directed away from the Sun). On July 04-05 solar wind parameters are expected to be slightly elevated due to the anticipated arrival of a mild high-speed stream from a small equatorial coronal hole with a negative polarity.

Geomagnetism

Geomagnetic conditions were mostly quiet with some unsettled period observed by the local stations (K-BEL: 1 to 3). Quiet to unsettled geomagnetic conditions are expected on July 04-05 due to the anticipated arrival of a mild high-speed stream from a small equatorial coronal hole with a negative polarity.

Proton flux levels

The greater than 10 MeV proton was at the nominal levels in the past 24 hours. The proton flux is expected to remain below 10 pfu threshold over the next day, with a small chance that a particle event occurs in association with an X-class flare or a coronal mass ejection.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux was above the 1000 pfu threshold for a short period. It is expected to remain close to the threshold for the next 24 hours. The 24-hour electron fluence was at moderate levels and it is expected to remain at moderate levels over the next 24 hours.

Today's estimated international sunspot number (ISN): 137, based on 15 stations.

Solar indices for 03 Jul 2023

Wolf number Catania	189
10cm solar flux	173
AK Chambon La Forêt	009
AK Wingst	006
Estimated Ap	006
Estimated international sunspot number	154 - Based on 24 stations

Noticeable events summary

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

All times in UTC

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