Mapping of Ionospheric F-Region Parameters from Atomic Oxygen Airglow Emissions

摘要

Simultaneous North-South scanning observations of the OI 7774 A and 6300 A nightglow emissions were carried out at Cachoeira Paulista, Brazil, to study the tropical F-region dynamics under spread-F and no spread-F conditions. From the observed emission intensities the ionospheric F-region peak electron densities and peak heights can be determined with a good spatial coverage both in latitude and longitude. Results are presented in the form of computer generated gray level shade maps showing the variations of the column intensities of the 7774 A emission (J7774) and of the 6300 A emission (J6300), as well as the variations of square root of (J7774) (related to F-region peak electron density) and of the ratio square root of (J7774)/J6300 (related to F-region peak height), as a function of zenith distance (latitude) and local time. Significant features of these observations are discussed. This technique is useful to study dynamic processes and large scale plasma irregularities in the nighttime tropical ionosphere.