The latitudinal, diurnal, and altitudinal distributions of upward flowing energetic ions of ionospheric origin

Abstract

Upward flowing fluxes of energetic (0.5‐16 keV) H+ and O+ ions are frequently observed by the ion mass spectrometer on the polar‐orbiting S3‐3 satellite. Data obtained on the first ∼370 orbits have been used to derive the occurrence frequency of these fluxes. The upward acceleration of ionospheric ions to keV energies is a persistent phenomenon generally occurring in a zone closely associated with the statistical auroral oval. Upward flowing ion events with flux above ∼2 × 106 keV/(cm² sec ster keV) are observed in more than 60% of the orbits. A strong dawn‐dusk asymmetry is found in the frequency of occurrence with the maximum in the dusk sector. The probability of observation increases with altitude up to apogee (8000 km) indicating that the main energization takes place preferentially at altitudes above ∼1 R E.

A statistical study of diurnal, seasonal and solar cycle variations of F-region and topside auroral upflows observed by EISCAT between 1984 and 1996

“…Previous statistical analyses of satellite data (e.g. Ghielmetti et al, 1978;Loranc et al, 1991) have revealed that the spatial distribution of up¯ows is auroral oval-like. A statistical study of transversely accelerated ions (TAIs), and subsequent ion up¯ow, by Klumpar (1979) revealed a similar distribution of events, although the author reported ion¯uxes that were one to two orders of magnitude less than those observed in the present study.…”

Solar wind control of Earth's H+ and O+ outflow rates in the 15‐eV to 33‐keV energy range

“…Magnetotail ion composition measurements in that energy range were first made more than 20 years ago on the ISEE 1 satellite, within 23 R E [Lennartsson and Shelley, 1986, and references therein], and are presently being made with the Cluster satellites within 19 R E [e.g., Rème et al, 2001]. Near-Earth ion composition measurements ($2 R E ) were begun even earlier with the polar-orbiting S3-3 satellite and were indeed the first to both detect the energetic ion outflow and provide substantial statistical material [e.g., Ghielmetti et al, 1978;Collin et al, 1981]. Similar measurements were subsequently extended as far as R $ 6 R E with the Prognoz-7 satellite [Lundin et al, 1983] and R $ 4.5 R E with the DE 1 satellite [e.g., Yau et al, 1984Yau et al, , 1985aYau et al, , 1985b, the latter being especially pivotal in that they were made continually over almost 10 years; that is almost a complete solar cycle.…”

Energetic-Particle Populations and Cosmic-Ray Entry

“…In support of the latter process, GHIELMETTI et al (1978) have reported the common occurrence of upward flowing energetic ions (both W and 0+) of ionospheric origin, especially in the afternoon and evening sectors (see Fig. 3).…”