Viewing archive of Sunday, 19 September 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Sep 19 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
19 Sep 2021	074	002
20 Sep 2021	076	001
21 Sep 2021	077	001

Bulletin

The solar activity was at low levels with only one detection of a C-class flare during the last 24 hours. The leading part of the newly numbered NOAA Active Region (AR) 2871 is now visible from Earth. This is the region that produce the C1.6 flare of today at 01:04 UT. Further C-class activity is expected from this AR in the next 24 hours.

No Earth-directed CMEs were detected in the available coronagraph imagery over the past 24 hours.

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

The Solar Wind (SW) parameters as observed by ACE and DSCOVR returned to a typical slow SW regime during the past 24 hours. The SW speed gradually dropped from 410 to 320 km/s, the total magnetic field strength (Btot) dropped from 7.7 to 2.6 nT and the vertical magnetic field component (Bz) varied between -3.9 and 5.9 nT in the last 24 hours. The interplanetary magnetic field angle (phi) was predominantly in the negative sector (directed towards the Sun) during the past 24 hours. The SW is expected to remain in a slow SW regime for the next 24 hours.

The geomagnetic conditions over the past 24 hours were globally and locally quiet (NOAA Kp index 0-2 and K Dourbes 1-2). They are expected to remain quiet both globally and locally in the next 24 hours.

Today's estimated international sunspot number (ISN): 012, based on 15 stations.

Solar indices for 18 Sep 2021

Wolf number Catania	///
10cm solar flux	074
AK Chambon La Forêt	008
AK Wingst	007
Estimated Ap	010
Estimated international sunspot number	000 - Based on 27 stations

Noticeable events summary

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

All times in UTC

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