INFO FROM SIDC - RWC BELGIUM 2015 Mar 17 12:30:09
Solar flaring activity continued to be dominated by NOAA AR 2297 but was low over the period, with the strongest flare of level C8.1 peaking at 20:49UT. A further handful of C flares (mostly low level) were produced by this region. A new (yet unnumbered) region is rotating on disc from behind the east limb around latitude N20. Active region 2297 remains the most prominent region on disc, with M flares likely form this region and X flaring possible. The 10 MeV proton levels have declined over the period but have not yet reached background levels. Proton events are quite possible in case of strong flaring from active region 2297 and in the wake of the arrival of the March 15 CME.
Around 14:08UT the long filament (or at least its southern part) south of AR 2297 can be seen to start lifting off in SDO AIA 304 images. Its subsequent eruption seems to be directed predominantly southward, although coronagraph images around that time are currently lacking. Solar wind conditions were dominated by the shock arrival associated with the March 15 CME, early this morning. Around 4:04UT solar wind speed jumped abruptly from around 410 km/s to over 500 km/s and is currently reaching 600-620 km/s. The total magnetic field increased from in the 8-10 nT range to the 24-28 nT range with Bz pronounced positive around the time of the jump. Also temperature and density increased at the shock although the density changed less abrupt and less pronounced. The total magnetic field remained meanwhile at levels mostly between 15-25 nT, with Bz negative over a significant part of the period (roughly 5:00UT to 9:00UT) and with negative peaks of under -22nT. The event was also related with rotation of the magnetic field phi angle. Local geomagnetic conditions remained initially quiet (K=2) but later reached minor storm levels (K=5). NOAA Kp showed minor storm levels right from the onset (K=5) and is even reaching moderate storm conditions. Solar wind conditions will first remain under the influence of the CME passage, with later possible influences of the extension of the southern coronal hole taking over as CME effects decline. Minor storm conditions are likely over the remainder of the day later declining to active conditions possibly persisting over the next 48 hours.