Viewing archive of Tuesday, 27 February 2018

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2018 Feb 27 1234 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
27 Feb 2018	071	021
28 Feb 2018	072	011
01 Mar 2018	071	006

Bulletin

Catania sunspot group 73 (NOAA AR 2700) is the only numbered sunspot group observed on the visible side of the solar disc. This sunspot group was the source of two weak B-class flares reported during last 24 hours. We expect occasional B-class flares in the coming hours, with the low possibility for isolated C-class flare. During last 24 hours there were no Earth directed CMEs reported, and the solar protons remained at background level.

As expected, the solar wind speed is slowly increasing and its present value is about 510 km/s, the interplanetary magnetic field (IMF) magnitude is also slightly elevated amounting about 10 nT. These increase of the solar wind speed and the magnitude of the IMF is due to arrival of the fast flow associated with the equatorial coronal hole (possibly connected to the southern polar coronal hole) which reached central meridian in the late evening of February 22. The fast solar wind and the longer interval of the negative value of the Bz component of the IMF (down to -9 nT) induced active geomagnetic conditions early this morning (NOAA reported Kp=5 and local station at Dourbes reported K=4). The geomagnetic conditions are presently unsettled to active and we expect such a geomagnetic conditions to continue in the coming hours.

Today's estimated international sunspot number (ISN): 017, based on 21 stations.

Solar indices for 26 Feb 2018

Wolf number Catania	016
10cm solar flux	070
AK Chambon La Forêt	023
AK Wingst	011
Estimated Ap	009
Estimated international sunspot number	018 - Based on 28 stations

Noticeable events summary

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

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