Viewing archive of Tuesday, 29 June 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jun 29 1230 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
29 Jun 2021	089	006
30 Jun 2021	089	011
01 Jul 2021	089	017

Bulletin

The largest flare of the past 24 hours was a C1.2 flare peaking at 19:11UT from NOAA region 2835 which has shown some intermediate spot formation and opposite polarity flux emergence. Region 2836 seems to have stabilized after its emergence yesterday. The new region in the North East (NOAA region 2837) appears to be unipolar. Flaring at C level is quite possible (most likely from NOAA 2835) over the next 24 hours.

A dimming is seen in SDO AIA imagery at around 5:16UT. It originates from around N15E10 which is the SouthEastern area of the large plage region in the Northern hemisphere. These signatures are indicative of a coronal mass ejection which, given location of the source region on disc, is likely to have an Earth directed component. However, coronagraph data so far do not display any clear signatures of such associated CME. A more conclusive assessment will be made as more coronagraph data come in. Around 20:00UT June 28 SoHO LASCO coronagraph data show a CME towards the North West with an angular width of around 135 degrees. It is seen as a halo from STEREO A location and is therefore backsided with respect to Earth.

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 was below the 1000 pfu event threshold. The 24h electron fluence was at normal levels and electron fluence is expected to remain at normal levels during the next days.

Nominal slow Solar wind conditions were observed. Solar wind speed was between 300-340 km/s and total magnetic field remained under 5nT. The magnetic field phi angle indicated that the interplanetary magnetic field is pointing away from the Sun. Solar wind conditions are expected to remain within a nominal slow Solar wind regime until tomorrow afternoon June 30 when an increase may be expected associated with the small coronal hole in the northern hemisphere that started transiting central meridian on Jun 27. Late on July 1, a possible glancing blow from the June 27 CME may add to the perturbed conditions. Another possible CME is also awaiting further analysis.

Geomagnetic conditions were quiet to unsettled (NOAA Kp 0-1, local K Dourbes 0-3). Geomagnetic conditions are expected to remain quiet, rising to unsettled conditions tomorrow afternoon.

Today's estimated international sunspot number (ISN): 054, based on 16 stations.

Solar indices for 28 Jun 2021

Wolf number Catania	///
10cm solar flux	089
AK Chambon La Forêt	007
AK Wingst	004
Estimated Ap	003
Estimated international sunspot number	044 - Based on 26 stations

Noticeable events summary

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

All times in UTC

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