Viewing archive of Monday, 28 June 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jun 28 1231 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
28 Jun 2021	088	007
29 Jun 2021	088	007
30 Jun 2021	088	011

Bulletin

Solar X-ray flux remained initially below C level but a C2 flare peaked at 9:35UT from the new region (NOAA active region 2836) that has emerged over the period, just to the South-West of NOAA active region 2835. There is also another region rotating onto the disc in the North East. Overall, C flaring is possible but not very probable.

A Westward CME is seen in SoHO/LASCO coronagraph data from around 4UT June 27 onwards. Its angular width is around 110 degrees. The same CME is visible from STEREO A COR 2 data, as directly Westward from STEREO A perspective. It is most likely associated to a dimming that can be seen just to the West of the disc center between 1-5UT. As a consequence the CME is estimated to be directed only just to the West of the Sun-Earth line and a glancing blow can not be excluded. It is measured to have a rather low speed of between 300-350 km/s and a possible arrival is therefore expected around the afternoon of July 1.

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 320-380 km/s and total magnetic field remained mostly 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 the afternoon of June 30 when an increase may be expected associated with the 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.

Geomagnetic conditions were quiet to unsettled (NOAA Kp 0-1, local K Dourbes 1-3). Geomagnetic conditions are expected to remain quiet, then rising to unsettled conditions in the afternoon of June 30.

Today's estimated international sunspot number (ISN): 043, based on 18 stations.

Solar indices for 27 Jun 2021

Wolf number Catania	///
10cm solar flux	087
AK Chambon La Forêt	007
AK Wingst	004
Estimated Ap	003
Estimated international sunspot number	033 - Based on 22 stations

Noticeable events summary

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

All times in UTC

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