Viewing archive of Wednesday, 29 September 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Sep 29 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
29 Sep 2021	089	007
30 Sep 2021	091	007
01 Oct 2021	093	014

Bulletin

Four active regions (ARs) present on the visible solar disk. NOAA AR 2871 has decayed from beta-gamma magnetic field configuration, to alpha. Two new ARs: NOAA AR 2880 (beta) and 2881 (alpha). The former produced a C1.3 flare peaking at 02:18 UT. There’s also a new region rotating into view. Over the next 24 hours, more C-class flares can be expected.

No Earth directed CMEs have been observed in the last 24 hours.

The greater than 10 MeV proton flux was at background levels in the past 24 hours, and is expected to stay there in the next 24 hours. The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold, it may increase over the next 24 hours. The electron fluence was at normal levels over the past 24 hours, it may increase over the next 24 hours.

The Earth is still inside the high speed solar wind from the low latitudinal extension of the northern polar coronal hole (positive polarity). Solar wind speeds have reached 550 km/s with magnetic fields up to 6 nT (with Bz up to -3 nT). Over the next 24 hours we expect a return to slow solar wind.

Geomagnetic conditions were quiet to unsettled for Kp (NOAA Kp 1-3) and reached active periods locally at Dourbes (K Dourbes 2-4) over the past 24 hours, quiet to unsettled conditions can be expected for the next 24 hours. An ICME is expected to arrive after 24 hours and produce active to moderate storm levels.

Today's estimated international sunspot number (ISN): 074, based on 12 stations.

Solar indices for 28 Sep 2021

Wolf number Catania	075
10cm solar flux	089
AK Chambon La Forêt	017
AK Wingst	013
Estimated Ap	012
Estimated international sunspot number	055 - Based on 23 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