Imaging science contributions to equatorial aeronomy: Initial results from the MISETA program

Abstract

Optical diagnostic techniques have been applied to studies of equatorial aeronomy for nearly half a century. The use of scanning photometers and two-dimensional imagers to observe the spatial patterns associated with low-latitude emissions has been an increasingly used approach during the last few decades. In this paper we review the rationale for the use of all-sky cameras at equatorial latitudes, with particular emphasis on the quantitative information about structures and dynamics that can be extracted from airglow images. The new imaging science instrument at Arequipa, Peru, constructed for the MISETA Program is used as a case study for such techniques. Results derived include: (a) occurrence patterns of several emission features, (b) onset and growth characteristics of airglow depletions associated with equatorial spread-F, (c) zonal plasma drifts and their altitude dependence, (d) gravity waves in the mesosphere, and (e) transient optical signatures of thermospheric dynamics associated with the midnight temperature maximum at low latitudes.