Viewing archive of Sunday, 23 September 2018

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2018 Sep 23 1259 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
23 Sep 2018	068	020
24 Sep 2018	067	013
25 Sep 2018	067	009

Bulletin

There are no numbered sunspot groups observed on the visible side of the Sun, and there were no flares reported during last 24 hours. We expect such a quiet flaring conditions to persist in the coming hours. During last 24 hours we did not observe any signatures of the possibly Earth directed CME and the solar protons remained at the background level.

The solar wind speed is presently about 450 km/s and the interplanetary magnetic field is 9 nT. This morning, at about 04:00 UT, the in situ observations showed change of the phi angel followed by the increase of the interplanetary magnetic field magnitude, solar wind speed and temperature. All this indicate possible arrival of the fast solar wind associated with negative equatorial coronal hole. During last 24 hours, minor storm geomagnetic conditions were reported. Local station at Dourbes reported intervals of K=5 lasting from about 21:00 UT until the midnight on September 22, while NOAA reported long interval of Kp=4. Presently geomagnetic conditions are quiet to unsettled. In the coming hours we might expect unsettled to active geomagnetic conditions (isolated intervals of the minor storm conditions are also not excluded), due to the possible arrival of the fast solar wind.

Today's estimated international sunspot number (ISN): 000, based on 13 stations.

Solar indices for 22 Sep 2018

Wolf number Catania	///
10cm solar flux	068
AK Chambon La Forêt	038
AK Wingst	029
Estimated Ap	031
Estimated international sunspot number	000 - Based on 25 stations

Noticeable events summary

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

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