2.7.1 https://spdx.org/licenses/ SPDX CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available SPASE metadata descriptions spase://NASA/Catalog/Svalgaard/Sector.Boundary.Crossing NASA Catalog L. Svalgaard's Interplanetary Sector Boundary Crossing List https://doi.org/10.48322/b9m5-f869 2026-02-02T13:10:26Z 2023-05-11T12:34:56.789 Updated to SPASE Version 2.5.0 if needed, Added DOI information, JMW 2026-02-02T13:10:26Z Added MetadataRightsList. Added ResourceType and NamingAuthority. Updated to 2.7.1. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. ZCB 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 is discussed at the "InformationURL" given below. 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. Leif Svalgaard for creating and maintaining this event list Leif Svalgaard 2022-01-01T00:00:00 Leif Svalgaard, Stanford University spase://SMWG/Person/Leif.Svalgaard DataProducer SB event list introductory page http://wso.stanford.edu/SB/SB.html Link to Svalgaard and other sector boundary crossing lists spase://VSPO/Catalog/Svalgaard_SB_List spase://VSPO/Catalog/Svalgaard/Sector.Boundary.Crossing spase://SMWG/Repository/WSO Online Open Sector boundary crossing list https://www.leif.org/research/sblist.txt Text SectorBoundaryCrossing 1926-01-29T00:00:00 -P1M As of 2/8/2012, last SB crossing was for 1/25/2012