Viewing archive of Wednesday, 4 September 2024

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2024 Sep 04 1255 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
04 Sep 2024	239	016
05 Sep 2024	239	011
06 Sep 2024	239	008

Solar Active Regions and flaring

The solar flaring activity was at high levels during the last 24 hours, with several C-class flares and M-class flares. The strongest flares were and M5.5 and M5.6 flare from NOAA active regions peaked at 13:22 and 13:31 UTC on Sep 04. During the flare, the source region was on the East limb around latitude 20 degrees south. NOAA AR 3806, AR 3807, and AR 3813 remained the complex regions on the disk (beta-gamma magnetic field configuration). The solar flaring activity is expected to be at moderate to high levels over the next 24 hours, possibly with few M-class flares and a chance for isolated X-class flares.

Coronal mass ejections

No Earth-directed CMEs were detected in the available coronagraph observations during the last 24 hours.

Coronal holes

A small negative polarity coronal hole (CH), spanning 30-50 S, has crossed the central meridian on Sep 03, and the associated high- speed stream from this CH may enhance the solar wind environment near Earth on Sep 4-5. Another small positive polarity CH, spanning 25 - 35 N, has started to cross the central meridian on Sep 02. The high-speed stream from this CH is expected to enhance the solar wind environment near Earth on Sep 5-7.

Solar wind

Earth was within the slow solar wind regime, with the solar wind speed ranging between 300 km/s and 350 km/s. The North-South component (Bz) fluctuated between -6 and 9 nT, while the interplanetary magnetic field strength varied between 5 nT and 12 nT. Slow solar wind conditions are expected to persist over the next 24 hours. However, today, on Sep 4 at 09:35 UTC, a shock was observed, with the interplanetary magnetic field increasing from 9 nT to 20 nT, and the solar wind speed rising from 320 km/s to 400 km/s. This solar wind shock could be associated with the coronal mass ejection (CME) from September 1. Solar wind conditions are expected to be enhanced in the coming days due to the effects of this solar wind shock, followed by further enhancements on Sep 6, likely due to the impact of the Sep 3 CME.

Geomagnetism

Geomagnetic conditions were globally and locally at quiet conditions (NOAA Kp and K-Dourbes 1 to 2). Following the solar wind shock observed today on Sep 4, at 09:35 UTC unsettled to active condition are expected in the next 24 hours.

Proton flux levels

The greater than 10 MeV GOES proton flux is still enhanced and remains below the 10 pfu threshold level. The greater than 50 MeV GOES proton flux and the greater than 100 MeV GOES proton flux started to increase around 09:10 UTC on Sep 03, and remain below the 10 pfu threshold level. The proton flux is expected to remain elevated, but below the threshold level in the coming hours. Still, there is a possibility to exceed the threshold level if there are any further high energy flares and eruptions.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by the GOES-16 satellite, was below the threshold level over the past 24 hours and is expected to remain so in the coming 24 hours. The 24h electron fluence is presently at normal levels, and it is expected to remain so in the next 24 hours.

Today's estimated international sunspot number (ISN): 171, based on 11 stations.

Solar indices for 03 Sep 2024

Wolf number Catania	///
10cm solar flux	///
AK Chambon La Forêt	007
AK Wingst	005
Estimated Ap	005
Estimated international sunspot number	177 - Based on 18 stations

Noticeable events summary

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

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