Viewing archive of Saturday, 21 March 2015

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2015 Mar 21 1230 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
21 Mar 2015	113	018
22 Mar 2015	113	040
23 Mar 2015	116	040

Bulletin

Solar activity has been low during the period. Only two low level C flares occurred. Flaring activity originating from NOAA active region 2297 seemed to persist while already behind the western limb and was observed as a C1.4 flare peaking at 00:18UT. The stronger long duration C1.7 flare peaking at 8:09UT originated from a region beyond the eastern limb in the northern hemisphere. In the southern hemisphere a new region appeared on disc near S10 and is numbered NOAA 2305. The potential for C flaring from the regions on disc is low but the probability of flaring associated with the region beyond the east limb can not yet be judged. Thus, quiet conditions are likely although some C-flaring remains quite possible. Proton levels are at background values and expected to remain so. No Earth directed CMEs have been recorded. Solar wind remained under the influence of the high speed stream from the southern negative polarity coronal hole. Solar wind speed even increased with values since 5:00 UT roughly in the 620-700 km/s range. Total magnetic field fluctuated only slightly around the 6.5 nT level mainly in the 5-8 nT range. Bz was variable in the +/-6nT range while the magnetic phi angle was stable in the negative sector. Geomagnetic conditions were quiet to active with a period of minor storm conditions around UT midnight (NOAA Kp 3-5, local K Dourbes 2-5 over the period). The influence of the negative polarity high speed stream is expected to decline with another high speed stream from an equatorial positive coronal hole taking over later on March 22 with an associated sector boundary crossing. Geomagnetic conditions may thus remain unsettled to active in the next 24 hours before rising to active to minor storm levels afterwards.

Today's estimated international sunspot number (ISN): 018, based on 12 stations.

Solar indices for 20 Mar 2015

Wolf number Catania	041
10cm solar flux	113
AK Chambon La Forêt	038
AK Wingst	024
Estimated Ap	027
Estimated international sunspot number	016 - Based on 18 stations

Noticeable events summary

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

All times in UTC

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