Viewing archive of Saturday, 15 April 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Apr 15 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
15 Apr 2023	174	011
16 Apr 2023	174	006
17 Apr 2023	174	005

Bulletin

The solar flaring activity over the past 24 hours has been at moderate levels with a total of 21 C-class flares and 2 M-class flares observed, while also showing a rising background level in the recorded X-ray activity. Most of the flaring originated from Catania sunspot group number 59 (NOAA AR 3282), from which also the 2 M-class flares originated. The strongest flare recorded was a M1.5 flare with peak time at 23:27 UT on April 14. A total of 8 numbered active regions are presently observed on the visible side of the solar disk, all with a simple configuration of their photospheric magnetic field (alpha or beta), except for Catania sunspot group number 57 (NOAA AR 3280) which has a beta-gamma configuration of its photospheric magnetic field. For the next 24 hours, we expect multiple C-class flares and possibly isolated M-class flares. The flaring activity originating from the Catania sunspot group number 57 (NOAA AR 3280), which is currently well-connected to the Earth, could be associated with a particle event.

During the last 24 hours there were no potentially Earth-directed coronal mass ejections (CMEs) detected in the available coronagraph observations.

The greater than 10 MeV proton flux was at nominal levels over the past 24 hours. Due to the moderate flaring activity it is possible that the greater than 10 MeV proton flux may exceed this threshold over the next 24 hours if there are any high energy flares and eruptions. The greater than 2 MeV electron flux has been below the 1000 pfu threshold and is expected to remain so. The 24h electron fluence was at normal levels and is expected to stay below the threshold over the next 24 hours.

Over the past 24 hours, the solar wind speed was in the slow solar wind regime with values between 320 km/s and 380km/s. The interplanetary magnetic field strength was about 6-8 nT with a varying North-South component of the magnetic field. For the next 24 hours, we expect Earth to be under the influence of the solar wind originating from the two positive polarity coronal holes which crossed the central meridian over the past days. Only minor geomagnetic impact of the upcoming fast wind is expected.

During the last 24 hours the geomagnetic conditions were quiet to unsettled and we expect quiet to unsettled geomagnetic conditions in the coming hours.

Today's estimated international sunspot number (ISN): 182, based on 13 stations.

Solar indices for 14 Apr 2023

Wolf number Catania	175
10cm solar flux	171
AK Chambon La Forêt	014
AK Wingst	008
Estimated Ap	007
Estimated international sunspot number	163 - Based on 14 stations

Noticeable events summary

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

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