The second largest solar flare this solar cycle (possibly the largest), a class X14 x-ray flare (possibly larger), was observed from departing active sunspot Region 9415 today at 13:49 UTC. Region 9415, which will be known as one of the super-power regions of solar cycle 23, is rotating beyond the west limb of the Sun. The activity and morphological structure of this region will undoubtably be the subject of intense study and scientific interest for years to come. It is, in a way, a fitting end to have this region produce such an intense solar x-ray flare within hours of its passage behind the west limb of the Sun. However, the effects of this most recent major flare may well be observed for several more days. This event was associated with exceptionally loud radio bursts. It also produced a prompt and spectrally hard proton event in the near-Earth space environment. This event produced protons with sufficient energy to punch through the Earth's polar ionosphere and produce an enhancement in ground-level neutron counts at the Thule, Greenland station. Although this increased radiation poses no threat to humans on the surface of the Earth, astronauts may have been required to take radiation avoidance measures. Spacecraft may also experience increased incidences of anomalous events such as single event upsets, phantom commands, star-tracker problems, etc. Space weather analysts are currently looking at the x-ray data from this flare. It is possible this flare (which at an X14 level would probably rank among the top 4 of the largest x-ray flares in recorded history) may have even been larger than that. There is a rumour floating around the professional community that suggests this flare may have been even larger than the estimated X22 flare earlier this month from departed active Region 9393. Once all of the x-ray data has been fully analyzed, it will be more possible to determine (quantitatively) where this flare ranks in history. This major flare may have produced a coronal mass ejection that could conceivably result in a minor impact on geomagnetic and auroral activity on or near 18 April. Although additional analysis will be performed over the next 24 hours to better ascertain the particulars, the likelihood of this event producing a major impact on auroral activity is relatively small given the very poor location of the flare on the west limb of the Sun. Most (perhaps virtually all) of the ejected mass would have been ejected far to the west of the Earth. The region has been in decay for several days now. Although there is the possibility we may observe another major flare over the next 24 to 48 hours before x-rays from this region are completely occulted by the Sun's disk, there is also a possibility this major flare may have been the last that this region will produce. Many forecasters do not expect the region will survive the two weeks it will take it to travel around the backside of the Sun and back into view on the eastern limb. Over the next several days, the remnants of old active Region 9393 (which was a naked-eye sunspot group arguably [see above] responsible for the largest x-ray flare [an X22 flare event] of this solar cycle) are due to rotate back into view around the east limb of the Sun. Although we do not expect anything very substantial to return, it will nonetheless be interesting to examine the remnants of this once powerful active sunspot group. Apr 12, 2001 Shift Report ------------------------- There was an X2 class flare and associated CME this morning. GOES hard proton rates have registered it. We can expect some rise in the soft proton rates to follow, and although the effects of previous shocks seem to be declining, there is currently a slight upward trend after a marked decline during the previous 24 hrs. The total environment for the upcoming orbit is difficult to predict, perhaps best labeled "unsettled" space weather. Apr 16, 2001 Shift Report -------------------------- ACE proton radiation is high but dropping at present. Recent high energy proton events could result in low energy proton flux increases.