Viewing archive of Friday, 19 March 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Mar 19 1230 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Quiet

	10cm flux	Ap
19 Mar 2021	073	007
20 Mar 2021	075	037
21 Mar 2021	077	031

Bulletin

Solar activity was very low in the past 24 hours. Catania group 81 (NOAA active region 2810 Alpha) is the only active region on disk. Solar activity is expected to remain at very low levels, with a very small chance of a C-class flare.

No Earth-directed CMEs have been observed in the available coronagraph data.

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 reached the 1000 pfu threshold during the first part of the period before gradually decreasing again. The greater than 2 MeV electron flux is expected to remain below the 1000 pfu threshold during the next 24 hours. The 24h electron fluence was at moderate levels in the last 24 hours and is expected to drop to nominal levels in the next 24 hours.

Solar wind conditions reflected a slow solar wind regime over the last 24 hours. The solar wind speed dropped further and ranged between 300 km/s and 350 km/s. The total interplanetary magnetic field varied between 1 nT and 5 nT. The magnetic field phi angle was predominantly in the negative sector (directed towards the Sun). The solar wind parameters are expected to become enhanced in the next 24 hours, due to the effect from the corotating interaction region (CIR) and high-speed stream associated with the negative polarity coronal hole, which crossed the central meridian on the 17th March.

Geomagnetic conditions were locally at quiet and globally quiet to unsettled levels (local K Dourbes 1-2 and NOAA Kp 0-3). Towards the end of the 19th March or early on the 20th, geomagnetic conditions are expected to increase to active levels, possibly reaching minor storm conditions. This is because of the expected arrival of a high-speed stream caused by the negative polarity coronal hole that crossed the central solar meridian on the 17th March.

Today's estimated international sunspot number (ISN): 013, based on 24 stations.

Solar indices for 18 Mar 2021

Wolf number Catania	///
10cm solar flux	073
AK Chambon La Forêt	011
AK Wingst	006
Estimated Ap	004
Estimated international sunspot number	012 - Based on 18 stations

Noticeable events summary

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

All times in UTC

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