Viewing archive of Thursday, 19 March 2015

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2015 Mar 19 1229 UTC

SIDC Forecast

Solar flares

Eruptive (C-class flares expected, probability >=50%)

Geomagnetism

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

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
19 Mar 2015	115	028
20 Mar 2015	113	026
21 Mar 2015	111	010

Bulletin

Solar activity was low with the strongest flare of the period remaining restricted to a C7.6 flare peaking at 16:31 from NOAA region 2297. Multiple other C class flares were observed from regions 2297 and 2302. A new region emerged near N16W17 while NOAA region 2297 showed some further decay. Flaring at C level is expected with a chance for M flares remaining but diminishing. There also remains a chance for a proton event in case of strong activity from region 2297 but this chance is also diminishing as the region further rotates towards and beyond the west limb over the next days. No Earth directed CMEs were observed. Following the decline of CME effects of the March 15 CME, solar wind conditions now appear to be under the influence of a high speed stream from the southern negative polarity coronal hole. Solar wind speed saw first an increase from around 560 km/s to a peak of over 760 km/s at 21:25UT, followed by a steady decline back to values around 560 km/s. The total magnetic field continued to decrease further during the period, from around 11 nT down to values of 4 nT after midnight. Since then, a slight increase back to current values approaching 8 nT was seen. Bz was variable with some negative peaks down to -10nT at the start of the period. The magnetic field phi angle was stable in the negative sector. The high speed stream influence is likely to persist but decline over the next 24-48 hours. Minor geomagnetic storm conditions dominated the first half of the period with even a moderate storm episode at planetary level (NOAA Kp 5-6, local K Dourbes 3-5). Current conditions are unsettled to active (NOAA Kp=4, K Dourbes 3-4) and likely to persist, with minor storm conditions possible.

Today's estimated international sunspot number (ISN): 039, based on 11 stations.

Solar indices for 18 Mar 2015

Wolf number Catania	///
10cm solar flux	115
AK Chambon La Forêt	059
AK Wingst	045
Estimated Ap	049
Estimated international sunspot number	032 - Based on 17 stations

Noticeable events summary

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

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