Tools and Models:Solar Wind Structures

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Solar Wind Structures

Ian Richardson (NASA/Goddard Space Flight Center and CRESST/University of Maryland) has characterized the near-Earth solar wind structures since 1963 (extended from 1972 in 2011). The "hourly" file gives the type of structure where:

1=Transients including Interplanetary Coronal Mass Ejections (ICMEs) and post-shock flows following ICME-driven shocks

2=Corotating High-Speed Streams (HSS)

3=Slow Interstream Wind (Vsw <~400 km/s)

0=Undetermined (usually from lack of solar wind data)

The structure identification is based mainly on examining solar wind plasma and magnetic field data from near-Earth spacecraft. During gaps in these data (a particular problem during 1983-1994, when near-Earth solar wind data were only provided by the Earth-orbiting IMP 8 spacecraft), some structural information has been inferred from other sources. For example, cosmic ray intensities from neutron monitors and the Goddard GME instrument on the IMP 8 spacecraft are used to identify Forbush decreases associated with the passage of shocks and ICMEs, and modulations during the passage of high-speed solar wind streams originating in coronal holes. Geomagnetic data can also be used, e.g., storm sudden commencements often indicate the passage of shocks, and intervals of enhanced activity recurring at the solar rotation period may indicate the passage of high-speed streams. ICME identification is discussed in Cane and Richardson (2003); a list of ICMEs since 1996 may be found here.

17 December 2010: Changed the definition of daily average to be the minimum of 1, 2 or 3 from 0000-2359 UT. 0 (missing) only if all 24 hours are missing. Previously, used 24 hours from 18 UT of the previous day to 1759 UT on the day of the average. This was found to be confusing and not very useful to put in 'memory', and so was dropped.

Solar Wind Structure (SWS) Lists

Acknowledgements: The hourly solar wind structure list was provided by Ian Richardson of the NASA Goddard Space Flight Center and CRESST/University of Maryland via the CEDAR Database at the National Center for Atmospheric Research, which is supported by the National Science Foundation.

References (must include at least 1 in any report):

Rules of the Road: Please contact Ian Richardson about your use of this data and offer co-authorship (except for student theses). This offer can be declined.