Gravity wave initiation of equatorial spread F: A case study

Abstract

Jicamarca and Altair radar data [Woodman and scale corresponds approximately to the echo LaHoz, 1976; Tsunoda et al., 1979; Tsunoda and intensity in decibels relative to the incoherent White, 1981], recent rocket results [Szuszczewicz scatter level at an electron density of 106 cm-3 et al., 1980; Rino et al., 1981; Kelley et al., at the same range.

Same night observations of spread‐F by the Jicamarca Radio Observatory in Peru and CUPRI in Alcântara, Brazil

“…Such appears to have been the case on one of the nights at Jicamarca used in this comparison, with the actual plume eruptions correlated with secondary rises in the F-layer. The similar spacings of the plumes supports theories of initiation mechanisms tied to gravity waves [Kelley et al, 1981], though other factors certainly play roles in these mechanisms. While one night exhibited strong plume activity at both sites, the other night described here had only plumes over Brazil.…”

Large‐scale structures in the equatorial ionosphere and their connection to the generalized Rayleigh‐Taylor instability

“…It is not feasible for large-scale disturbances to develop without the help of seeding [Kelley, 2009]. Gravity waves can trigger a R-T instability, both by providing an initial perturbation and by affecting the stability condition, as postulated in Röttger [1973], Klostermeyer [1978], and Kelley et al [1981]. Nicolls and Kelley [2005] presented evidence of gravity wave seeding of ionospheric plasma instabilities.…”

Postsunset vortex in equatorial F‐region plasma drifts and implications for bottomside spread‐F

“…What we are describing here (except for some geometrical differences) is the neutral wind driven component of the generalized Rayleigh-Taylor instability [e.g., Kelley et al, 1981] …”