L. Svalgaard's Interplanetary Sector Boundary Crossing List

This list of interplanetary sector boundary crossings,
now spanning 1926-2011, has been compiled by Leif Svalgaard from ground magnetometer data and in situ interplanetary magnetic field observations Identification of the boundaries. For each crossing, the day of crossing, the direction of
crossing (+to- or -to+) and the durations (in whole days) of single-polarity intervals on either side of the crossing are given. As of early 2012, the list was being kept current.