Extreme longitudinal variability of plasma structuring in the equatorial ionosphere on a magnetically quiet equinoctial day
Article first published online: 6 SEP 2006
Copyright 2006 by the American Geophysical Union.
Volume 41, Issue 6, December 2006
How to Cite
2006), Extreme longitudinal variability of plasma structuring in the equatorial ionosphere on a magnetically quiet equinoctial day, Radio Sci., 41, RS6S24, doi:10.1029/2005RS003366., , , , , , , , , and (
- Issue published online: 6 SEP 2006
- Article first published online: 6 SEP 2006
- Manuscript Accepted: 17 MAY 2006
- Manuscript Revised: 14 APR 2006
- Manuscript Received: 2 SEP 2005
- data assimilation
 We investigate the extreme longitudinal variability of equatorial scintillation under quiet magnetic conditions during 22–23 March 2002. Scintillation Network Decision Aid (SCINDA) observations show intense activity in the South American–Atlantic sector during local evening hours, whereas an absence of scintillation is seen in the far east Asian sector. Ground- and space-based measurements from SCINDA, the Global Ultraviolet Imager (GUVI), TOPEX, and a chain of GPS receivers are used in combination with the Utah State University Global Assimilation of Ionospheric Measurements (USU-GAIM) model to explore the relationship between the large-scale ionization distribution and small-scale irregularities at low latitudes in both the scintillating and nonscintillating longitude sectors. Our analysis shows that there are significant differences in the evolution of the ionization distributions during the evening hours, which are likely the result of differences in the daytime and postsunset vertical plasma drift in the two sectors. This study demonstrates the importance of USU-GAIM as a new tool for investigating longitudinal as well as day-to-day variability that is observed in the large-scale distribution of the ionosphere and how this relates to the occurrence of scintillation.