Long term periodicity in solar wind velocity during the last three solar cycles

• Published in: Geophysical research letters Vol. 22; no. 10; pp. 1165 - 1168
• Main Authors: Gazis, P. R., Richardson, J. D., Paularena, K. I.
• Format: Journal Article
• Language: English
• Published: Legacy CDMS Blackwell Publishing Ltd 15.05.1995; American Geophysical Union
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; Geophysics; Heliosphere; IMP; Interplanetary space; Solar cycles; Solar maximum; Solar Physics; Solar system; Solar wind plasma; Solar wind velocity; Spacecraft; Venus; Heliosphere; Solar wind; Velocity; Periodicity
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/95GL01017

Solar wind measurements from the Pioneer 10, Pioneer 11, Voyager 2, IMP 8, and Pioneer Venus Orbiter (PVO) spacecraft were examined to search for long-term periodicities during the last three solar cycles. For the time of the last solar maximum, these measurements confirm the existence of the periodic 1.3-year enhancements in solar wind velocity reported by Richardson et al. (1994). For most of the preceding two solar cycles, long-term velocity enhancements occurred that were similar in structure but lacked the 1.3-year periodicity. It appears that long-term enhancements in solar wind velocity, with durations on the order of a few months to a year, are a common feature throughout the heliosphere.