Viewing archive of Saturday, 9 October 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Oct 09 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
09 Oct 2021	085	007
10 Oct 2021	085	007
11 Oct 2021	085	007

Bulletin

The solar activity has been active over the past 24 hours. The Catania sunspots group 58 (NOAA AR-2882) has produced a C2.7-class flare peaking at 19:56 UTC on Oct 8 and a M1.6-class flare peaking at 06:38 UTC on Oct 9. More C-class flares are expected with a very a small chance of M-class flare.

A halo coronal mass ejection has been observed in the available SOHO/LASCO coronagraph imagery at 07:24 UTC on Oct 9. This halo coronal mass ejection is associated with the M1.6-class flare peaking at 06:38 UTC on the same day located on the central meridian in the Catania sunspots group 58 (NOAA AR-2882). The projected speed was measured about 692 km/s by the software package CACTus. The true speed was estimated around 950 km/s. The transit time to Earth is estimated to take about 62 hours, and the arrival time would be on Oct 12, around 01:00 UTC.

The greater than 10 MeV proton flux was at nominal levels in the past 24 hours, and is expected to stay at nominal levels in the next 24 hours. The greater than 2 MeV electron flux was below the 1000 pfu and at nominal levels in the past 24 hours, and is expected to stay at nominal levels in the next 24 hours. The greater than 2 MeV electron fluence was at nominal levels in the past 24 hours, and is expected to stay at nominal levels in the next 24 hours.

The Earth remained under the slow solar wind speed regime (ranging between 274 km/s and 304 km/) over the past 24 hours. The solar wind parameters (as observed by ACE and DSCOVR) showed an ambient background solar wind flow with interplanetary magnetic field magnitude values returning below 5.0 nT and its Bz components fluctuating between -4.0 nT and 4.0 nT. Nominal solar wind regime is expected to persist in the next 24 hours. Later, on Oct 12, enhancement of the solar wind parameters are expected due to the arrival of the halo coronal mass ejection observed in the coronagraph imagery at 07:24 UTC on Oct 9.

The geomagnetic conditions were mostly quiet (with short periods of unsettled condition observed at the local station in Dourbes) over the past 24 hours. Quiet conditions are expected to remain as long as the Earth remains in slow solar wind speed regime.

Today's estimated international sunspot number (ISN): 023, based on 17 stations.

Solar indices for 08 Oct 2021

Wolf number Catania	018
10cm solar flux	092
AK Chambon La Forêt	007
AK Wingst	004
Estimated Ap	003
Estimated international sunspot number	017 - Based on 29 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page