Viewing archive of Monday, 18 October 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Oct 18 1247 UTC

SIDC Forecast

Solar flares

Quiet conditions (<50% probability of C-class flares)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
18 Oct 2021	079	015
19 Oct 2021	081	021
20 Oct 2021	082	008

Bulletin

Solar activity was at very low levels. A new region has just rotated over the east solar limb (S18E74, Catania sunspot region 64) for which an accurate assessment of the magnetic field complexity is not yet possible. Additionally, a small sunspot has emerged in the western hemisphere (Catania sunspot region 63) but has not produced any activity. Solar activity is expected to be very low over the next 24 hours with a low probability of C-class flares from the new active region that has just rotated onto the solar disk.

No Earth directed CMEs have been detected in the available coronagraph imagery.

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

The solar wind measurements by DSCOVR over the past 24 hours showed some enhancements in the Interplanetary Magnetic Field (IMF). The total magnetic field increased to a maximum value of 13 nT. The Bz varied between -9 and +11 nT and had an extended period of negative Bz until 03 UT Oct 18. The solar wind speed ranged between 315 km/s and 380 km/s. The solar wind speed and magnetic field are expected to be enhanced on Oct 18 and 19, due to the arrival the High Speed Stream (HSS) associated with the with the small positive Coronal Hole (CH) and subsequently the larger negative polarity extension of the southern polar CH which began to cross the central meridian on Oct 16.

Geomagnetic conditions reached active levels (NOAA Kp and local K Dourbes 2-4 and 1-3, respectively) over the past 24 hours in response to the extended period of negative Bz. Geomagnetic conditions are expected to be active on Oct 18 and Oct 19, with minor storm conditions possible, due to the arrival of the aforementioned HSS.

Today's estimated international sunspot number (ISN): 017, based on 18 stations.

Solar indices for 17 Oct 2021

Wolf number Catania	///
10cm solar flux	077
AK Chambon La Forêt	///
AK Wingst	///
Estimated Ap	///
Estimated international sunspot number	000 - Based on 26 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