Просмотр архива за среда, 13 апреля 2022

Daily bulletin on solar and geomagnetic activity from the SIDC

Существующий: 2022 Apr 13 1255 UTC

SIDC Forecast

Солнечные вспышки

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

Geomagnetism

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

Солнечные протоны

Quiet

	10cm flux	Ap
13 Apr 2022	096	015
14 Apr 2022	095	014
15 Apr 2022	097	013

Bulletin

After the Catania sunspot groups 73 and 66 (NOAA ARs 2983 and 2982, respectively) rotated behind the west solar limb the solar flaring activity strongly decreased and only one B-class flare was reported today. We expect such a low level of flaring activity to persist in the coming hours. No Earth-directed CMEs were detected in the available coronagraph observations over the past 24 hours.

The greater than 10 MeV proton flux was at background levels, and we expect that it will remain so in the coming hours. The greater than 2 MeV electron flux was most of the time under the 1000 pfu threshold, with only short intervals reaching and crossing the threshold. We expect the 2 MeV electron flux will remain on these levels in the coming hours. The 24h electron fluence is at normal to moderate level and we expect it will stay so in the coming 24 hours.

The in situ observations show that the sudden increase of the interplanetary magnetic filed magnitude, the solar wind speed, density and temperature at about 10:20 UT on April 12 was the shock, which was afterwards followed by the ICME. The solar origin of this ICME is somewhat unclear, as there are two possible candidates: the CME observed on April 07, and the CME observed on April 09. However, the presently observed solar wind velocity indicates that the CME most probably departed the Sun on April 09, and that it was associated with the large filament eruption from the southwest quadrant of the Sun.

Rather small, positive polarity equatorial coronal hole crossed central meridian early evening of April 12. The fast solar wind, originating from this coronal hole can be expected in the morning of April 16. The halo CME (first observed in the SOHO/LASCO C2 filed of view at about 05:48 UT on April 11) is expected to arrive to Earth in the late afternoon of April 14, and it might induce active geomagnetic conditions.

Due to the arrival of the ICME the Bz component of the interplanetary magnetic field was negative (down to about -6 nT), during eight hours this morning, while the solar wind velocity had the value of about 470 km/s. That resulted in the unsettled geomagnetic conditions as reported by local station at Dourbes (long interval of K=3) while at the same time NOAA reported long interval of Kp=4. The geomagnetic conditions are presently unsettled and we expect unsettled to quiet geomagnetic conditions in the coming hours.

Today's estimated international sunspot number (ISN): 031, based on 15 stations.

Solar indices for 12 Apr 2022

Wolf number Catania	012
10cm solar flux	096
AK Chambon La Forêt	022
AK Wingst	015
Estimated Ap	015
Estimated international sunspot number	013 - Based on 26 stations

Noticeable events summary

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

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