A Summary of Significant Solar-Initiated Events during STIP Intervals I and II.

摘要

Using data available at the present time, a summary of the significant solarterrestrial events that occurred during STIP Interval I(September-October 1975) and STIP Interval II (15 Mar-15 May 1976) has been prepared. The principal events during STIP Interval II were associated with solar activity in a region at Carrington Longitude about 45 deg (designated McMath Plage 14143 during solar rotation 1639 and designated McMath Plage 14179 during solar rotation 1640). Among the events summarized are the following: Solar activity during the period 20-23 March from a region behind the eastern limb of the sun. This was followed by the observation, on 6 April, of an increase in solar wind velocity at about 9.7 AU possible associated with a solar event behind the eastern limb of the sun on 20 March; a large geomagnetic storm with intense mid-latitude auroral activity on 26 March; moderate solar particle intensities at the earth from 26 March through 31 March; and a ground-level solar cosmic ray event on 30 April (12% increase at Inuvik, Canada) having a very hard spectrum and only moderate polar cap absorption (2.7 dB at Thule, Greenland) followed by a large geomagnetic disturbance on 2-3 May 1976.