Morphology of the postsunset vortex in the equatorial ionospheric plasma drift

• Autores: Lee, Woo Kyoung, Kil, Hyosub, Kwak, Young-Sil, Paxton, Larry J.
• Formato: artículo
• Fecha de Publicación: 2014
• Institución: Instituto Geofísico del Perú
• Repositorio: IGP-Institucional
• Lenguaje: inglés
• OAI Identifier: oai:repositorio.igp.gob.pe:20.500.12816/3617
• Enlace del recurso: http://hdl.handle.net/20.500.12816/3617; https://doi.org/10.1002/2014GL062019
• Nivel de acceso: acceso abierto
• Materia: Postsunset vortex; Zonal plasma drift; Zonal shear flow; Equatorial spread F; Equatorial ionosphere; http://purl.org/pe-repo/ocde/ford#1.05.01

The postsunset vortex in the equatorial ionosphere exhibits clockwise plasma motions after sunset in longitude (time) and altitude coordinates when the equatorial ionosphere is viewed looking northward. We describe the typical morphology of the postsunset vortex using incoherent scatter radar observations at Jicamarca in Peru during the previous solar maximum (2000–2002). A pronounced vortical plasma motion appears around 1700 LT along with the onset of the prereversal enhancement (PRE). The center of this vortex is located near an altitude of 270 km. A smaller‐scale vortex also appears about 0.5 ~ 1 h later at higher altitudes. However, the morphology and occurrence time of this small vortex depend on the characteristics of the coherent backscatter region. We find that the earlier vortex is the major feature of the postsunset vortices because it is repeatable, associated with the PRE, and independent to the occurrence of the coherent backscatter region.