Succession of Flares, CMEs Upsets Spacecraft,
Presages Solar Maximum
From April 27 through May 6, ISTP spacecraft and observatories got
of what is to come during the maximum of the solar cycle. In the
10 days, the Sun produced seven coronal mass ejections, two X-class
(the most energetic type), and at least two energetic particle
Earth, several major magnetic storms upset several spacecraft,
auroras to lower-than-normal latitudes, and forced power companies
reconfigure the grid in New England.
On April 29, a "halo" CME left the Sun and its shock arrived at the
spacecraft within 53 hours. The shock arrived faster than any
detected so far by SOHO. A magnetic storm followed on May 2.
rumors and anecdotal reports, the failure of the Equator-S
not necessarily a result of CME or magnetic storm.
ISTP observers have noted that sunspots are becoming more
moving with a clockwise rotation--telltale properties of proton
On May 1-2, ISTP observed two halo CMEs, as well as an X-class
High-energy protons from the flare arrived at SOHO within 30
a major magnetic storm developed on May 4.
During the storm, the disturbance storm-time index (Dst) reached
the scale of 0 to -220. It is the largest storm of the current
An ISTP ground station (CANOPUS) measured electric currents in the
ionosphere well above 2000 nanotesla, about 3-4 times the norm for
minimum. The January 1997 event that knocked out Telstar 401 had
of 1800 nT.
In response to the magnetic storm, power companies in New England
their power sharing capacity with Canadian utilities. Auroras were
reported as far south as Boston and Chicago.